1 | /* |
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2 | * Copyright 1997, Regents of the University of Minnesota |
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3 | * |
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4 | * minitpart2.c |
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5 | * |
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6 | * This file contains code that performs the initial partition of the |
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7 | * coarsest graph |
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8 | * |
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9 | * Started 7/23/97 |
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10 | * George |
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11 | * |
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12 | * $Id: minitpart2.c,v 1.1 1998/11/27 17:59:23 karypis Exp $ |
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13 | * |
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14 | */ |
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15 | |
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16 | #include <metis.h> |
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17 | |
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18 | /************************************************************************* |
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19 | * This function computes the initial bisection of the coarsest graph |
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20 | **************************************************************************/ |
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21 | void MocInit2WayPartition2(CtrlType *ctrl, GraphType *graph, float *tpwgts, float *ubvec) |
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22 | { |
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23 | int dbglvl; |
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24 | |
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25 | dbglvl = ctrl->dbglvl; |
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26 | IFSET(ctrl->dbglvl, DBG_REFINE, ctrl->dbglvl -= DBG_REFINE); |
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27 | IFSET(ctrl->dbglvl, DBG_MOVEINFO, ctrl->dbglvl -= DBG_MOVEINFO); |
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28 | |
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29 | IFSET(ctrl->dbglvl, DBG_TIME, starttimer(ctrl->InitPartTmr)); |
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30 | |
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31 | switch (ctrl->IType) { |
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32 | case IPART_GGPKL: |
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33 | case IPART_RANDOM: |
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34 | MocGrowBisection2(ctrl, graph, tpwgts, ubvec); |
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35 | break; |
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36 | case 3: |
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37 | MocGrowBisectionNew2(ctrl, graph, tpwgts, ubvec); |
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38 | break; |
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39 | default: |
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40 | errexit("Unknown initial partition type: %d\n", ctrl->IType); |
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41 | } |
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42 | |
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43 | IFSET(ctrl->dbglvl, DBG_IPART, printf("Initial Cut: %d\n", graph->mincut)); |
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44 | IFSET(ctrl->dbglvl, DBG_TIME, stoptimer(ctrl->InitPartTmr)); |
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45 | ctrl->dbglvl = dbglvl; |
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46 | |
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47 | } |
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48 | |
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49 | |
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50 | |
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51 | |
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52 | /************************************************************************* |
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53 | * This function takes a graph and produces a bisection by using a region |
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54 | * growing algorithm. The resulting partition is returned in |
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55 | * graph->where |
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56 | **************************************************************************/ |
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57 | void MocGrowBisection2(CtrlType *ctrl, GraphType *graph, float *tpwgts, float *ubvec) |
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58 | { |
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59 | int i, j, k, nvtxs, ncon, from, bestcut, mincut, nbfs; |
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60 | idxtype *bestwhere, *where; |
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61 | |
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62 | nvtxs = graph->nvtxs; |
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63 | |
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64 | MocAllocate2WayPartitionMemory(ctrl, graph); |
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65 | where = graph->where; |
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66 | |
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67 | bestwhere = idxmalloc(nvtxs, "BisectGraph: bestwhere"); |
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68 | nbfs = 2*(nvtxs <= ctrl->CoarsenTo ? SMALLNIPARTS : LARGENIPARTS); |
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69 | bestcut = idxsum(graph->nedges, graph->adjwgt); |
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70 | |
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71 | for (; nbfs>0; nbfs--) { |
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72 | idxset(nvtxs, 1, where); |
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73 | where[RandomInRange(nvtxs)] = 0; |
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74 | |
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75 | MocCompute2WayPartitionParams(ctrl, graph); |
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76 | |
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77 | MocBalance2Way2(ctrl, graph, tpwgts, ubvec); |
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78 | |
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79 | MocFM_2WayEdgeRefine2(ctrl, graph, tpwgts, ubvec, 4); |
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80 | |
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81 | MocBalance2Way2(ctrl, graph, tpwgts, ubvec); |
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82 | MocFM_2WayEdgeRefine2(ctrl, graph, tpwgts, ubvec, 4); |
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83 | |
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84 | if (bestcut > graph->mincut) { |
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85 | bestcut = graph->mincut; |
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86 | idxcopy(nvtxs, where, bestwhere); |
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87 | if (bestcut == 0) |
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88 | break; |
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89 | } |
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90 | } |
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91 | |
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92 | graph->mincut = bestcut; |
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93 | idxcopy(nvtxs, bestwhere, where); |
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94 | |
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95 | GKfree(&bestwhere, LTERM); |
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96 | } |
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97 | |
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98 | |
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99 | |
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100 | |
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101 | |
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102 | |
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103 | /************************************************************************* |
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104 | * This function takes a graph and produces a bisection by using a region |
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105 | * growing algorithm. The resulting partition is returned in |
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106 | * graph->where |
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107 | **************************************************************************/ |
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108 | void MocGrowBisectionNew2(CtrlType *ctrl, GraphType *graph, float *tpwgts, float *ubvec) |
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109 | { |
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110 | int i, j, k, nvtxs, ncon, from, bestcut, mincut, nbfs; |
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111 | idxtype *bestwhere, *where; |
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112 | |
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113 | nvtxs = graph->nvtxs; |
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114 | |
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115 | MocAllocate2WayPartitionMemory(ctrl, graph); |
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116 | where = graph->where; |
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117 | |
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118 | bestwhere = idxmalloc(nvtxs, "BisectGraph: bestwhere"); |
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119 | nbfs = 2*(nvtxs <= ctrl->CoarsenTo ? SMALLNIPARTS : LARGENIPARTS); |
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120 | bestcut = idxsum(graph->nedges, graph->adjwgt); |
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121 | |
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122 | for (; nbfs>0; nbfs--) { |
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123 | idxset(nvtxs, 1, where); |
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124 | where[RandomInRange(nvtxs)] = 0; |
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125 | |
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126 | MocCompute2WayPartitionParams(ctrl, graph); |
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127 | |
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128 | MocInit2WayBalance2(ctrl, graph, tpwgts, ubvec); |
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129 | |
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130 | MocFM_2WayEdgeRefine2(ctrl, graph, tpwgts, ubvec, 4); |
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131 | |
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132 | if (bestcut > graph->mincut) { |
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133 | bestcut = graph->mincut; |
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134 | idxcopy(nvtxs, where, bestwhere); |
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135 | if (bestcut == 0) |
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136 | break; |
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137 | } |
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138 | } |
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139 | |
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140 | graph->mincut = bestcut; |
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141 | idxcopy(nvtxs, bestwhere, where); |
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142 | |
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143 | GKfree(&bestwhere, LTERM); |
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144 | } |
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145 | |
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146 | |
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147 | |
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148 | /************************************************************************* |
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149 | * This function balances two partitions by moving the highest gain |
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150 | * (including negative gain) vertices to the other domain. |
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151 | * It is used only when tha unbalance is due to non contigous |
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152 | * subdomains. That is, the are no boundary vertices. |
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153 | * It moves vertices from the domain that is overweight to the one that |
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154 | * is underweight. |
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155 | **************************************************************************/ |
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156 | void MocInit2WayBalance2(CtrlType *ctrl, GraphType *graph, float *tpwgts, float *ubvec) |
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157 | { |
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158 | int i, ii, j, k, l, kwgt, nvtxs, nbnd, ncon, nswaps, from, to, pass, me, cnum, tmp, imin; |
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159 | idxtype *xadj, *adjncy, *adjwgt, *where, *id, *ed, *bndptr, *bndind; |
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160 | idxtype *moved, *perm, *qnum; |
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161 | float *nvwgt, *npwgts, minwgt; |
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162 | PQueueType parts[MAXNCON][2]; |
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163 | int higain, oldgain, mincut; |
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164 | |
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165 | nvtxs = graph->nvtxs; |
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166 | ncon = graph->ncon; |
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167 | xadj = graph->xadj; |
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168 | adjncy = graph->adjncy; |
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169 | nvwgt = graph->nvwgt; |
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170 | adjwgt = graph->adjwgt; |
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171 | where = graph->where; |
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172 | id = graph->id; |
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173 | ed = graph->ed; |
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174 | npwgts = graph->npwgts; |
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175 | bndptr = graph->bndptr; |
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176 | bndind = graph->bndind; |
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177 | |
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178 | moved = idxwspacemalloc(ctrl, nvtxs); |
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179 | perm = idxwspacemalloc(ctrl, nvtxs); |
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180 | qnum = idxwspacemalloc(ctrl, nvtxs); |
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181 | |
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182 | /* This is called for initial partitioning so we know from where to pick nodes */ |
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183 | from = 1; |
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184 | to = (from+1)%2; |
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185 | |
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186 | if (ctrl->dbglvl&DBG_REFINE) { |
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187 | printf("Parts: ["); |
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188 | for (l=0; l<ncon; l++) |
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189 | printf("(%.3f, %.3f) ", npwgts[l], npwgts[ncon+l]); |
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190 | printf("] T[%.3f %.3f], Nv-Nb[%5d, %5d]. ICut: %6d, LB: %.3f [B]\n", tpwgts[0], tpwgts[1], graph->nvtxs, graph->nbnd, graph->mincut, ComputeLoadImbalance(ncon, 2, npwgts, tpwgts)); |
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191 | } |
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192 | |
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193 | for (i=0; i<ncon; i++) { |
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194 | PQueueInit(ctrl, &parts[i][0], nvtxs, PLUS_GAINSPAN+1); |
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195 | PQueueInit(ctrl, &parts[i][1], nvtxs, PLUS_GAINSPAN+1); |
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196 | } |
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197 | |
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198 | idxset(nvtxs, -1, moved); |
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199 | |
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200 | ASSERT(ComputeCut(graph, where) == graph->mincut); |
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201 | ASSERT(CheckBnd(graph)); |
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202 | ASSERT(CheckGraph(graph)); |
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203 | |
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204 | /* Compute the queues in which each vertex will be assigned to */ |
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205 | for (i=0; i<nvtxs; i++) |
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206 | qnum[i] = samax(ncon, nvwgt+i*ncon); |
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207 | |
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208 | /* Insert the nodes of the proper partition in the appropriate priority queue */ |
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209 | RandomPermute(nvtxs, perm, 1); |
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210 | for (ii=0; ii<nvtxs; ii++) { |
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211 | i = perm[ii]; |
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212 | if (where[i] == from) { |
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213 | if (ed[i] > 0) |
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214 | PQueueInsert(&parts[qnum[i]][0], i, ed[i]-id[i]); |
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215 | else |
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216 | PQueueInsert(&parts[qnum[i]][1], i, ed[i]-id[i]); |
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217 | } |
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218 | } |
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219 | |
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220 | /* |
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221 | for (i=0; i<ncon; i++) |
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222 | printf("Queue #%d has %d %d\n", i, parts[i][0].nnodes, parts[i][1].nnodes); |
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223 | */ |
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224 | |
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225 | /* Determine the termination criterion */ |
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226 | imin = 0; |
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227 | for (i=1; i<ncon; i++) |
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228 | imin = (ubvec[i] < ubvec[imin] ? i : imin); |
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229 | minwgt = .5/ubvec[imin]; |
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230 | |
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231 | mincut = graph->mincut; |
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232 | nbnd = graph->nbnd; |
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233 | for (nswaps=0; nswaps<nvtxs; nswaps++) { |
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234 | /* Exit as soon as the minimum weight crossed over */ |
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235 | if (npwgts[to*ncon+imin] > minwgt) |
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236 | break; |
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237 | |
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238 | if ((cnum = SelectQueueOneWay2(ncon, npwgts+to*ncon, parts, ubvec)) == -1) |
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239 | break; |
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240 | |
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241 | if ((higain = PQueueGetMax(&parts[cnum][0])) == -1) |
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242 | higain = PQueueGetMax(&parts[cnum][1]); |
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243 | |
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244 | mincut -= (ed[higain]-id[higain]); |
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245 | saxpy(ncon, 1.0, nvwgt+higain*ncon, 1, npwgts+to*ncon, 1); |
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246 | saxpy(ncon, -1.0, nvwgt+higain*ncon, 1, npwgts+from*ncon, 1); |
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247 | |
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248 | where[higain] = to; |
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249 | moved[higain] = nswaps; |
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250 | |
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251 | if (ctrl->dbglvl&DBG_MOVEINFO) { |
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252 | printf("Moved %6d from %d(%d). [%5d] %5d, NPwgts: ", higain, from, cnum, ed[higain]-id[higain], mincut); |
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253 | for (l=0; l<ncon; l++) |
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254 | printf("(%.3f, %.3f) ", npwgts[l], npwgts[ncon+l]); |
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255 | printf(", LB: %.3f\n", ComputeLoadImbalance(ncon, 2, npwgts, tpwgts)); |
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256 | if (ed[higain] == 0 && id[higain] > 0) |
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257 | printf("\t Pulled from the interior!\n"); |
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258 | } |
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259 | |
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260 | |
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261 | /************************************************************** |
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262 | * Update the id[i]/ed[i] values of the affected nodes |
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263 | ***************************************************************/ |
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264 | SWAP(id[higain], ed[higain], tmp); |
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265 | if (ed[higain] == 0 && bndptr[higain] != -1 && xadj[higain] < xadj[higain+1]) |
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266 | BNDDelete(nbnd, bndind, bndptr, higain); |
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267 | if (ed[higain] > 0 && bndptr[higain] == -1) |
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268 | BNDInsert(nbnd, bndind, bndptr, higain); |
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269 | |
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270 | for (j=xadj[higain]; j<xadj[higain+1]; j++) { |
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271 | k = adjncy[j]; |
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272 | oldgain = ed[k]-id[k]; |
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273 | |
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274 | kwgt = (to == where[k] ? adjwgt[j] : -adjwgt[j]); |
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275 | INC_DEC(id[k], ed[k], kwgt); |
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276 | |
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277 | /* Update the queue position */ |
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278 | if (moved[k] == -1 && where[k] == from) { |
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279 | if (ed[k] > 0 && bndptr[k] == -1) { /* It moves in boundary */ |
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280 | PQueueDelete(&parts[qnum[k]][1], k, oldgain); |
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281 | PQueueInsert(&parts[qnum[k]][0], k, ed[k]-id[k]); |
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282 | } |
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283 | else { /* It must be in the boundary already */ |
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284 | if (bndptr[k] == -1) |
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285 | printf("What you thought was wrong!\n"); |
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286 | PQueueUpdate(&parts[qnum[k]][0], k, oldgain, ed[k]-id[k]); |
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287 | } |
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288 | } |
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289 | |
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290 | /* Update its boundary information */ |
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291 | if (ed[k] == 0 && bndptr[k] != -1) |
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292 | BNDDelete(nbnd, bndind, bndptr, k); |
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293 | else if (ed[k] > 0 && bndptr[k] == -1) |
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294 | BNDInsert(nbnd, bndind, bndptr, k); |
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295 | } |
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296 | |
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297 | ASSERTP(ComputeCut(graph, where) == mincut, ("%d != %d\n", ComputeCut(graph, where), mincut)); |
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298 | |
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299 | } |
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300 | |
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301 | if (ctrl->dbglvl&DBG_REFINE) { |
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302 | printf("\tMincut: %6d, NBND: %6d, NPwgts: ", mincut, nbnd); |
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303 | for (l=0; l<ncon; l++) |
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304 | printf("(%.3f, %.3f) ", npwgts[l], npwgts[ncon+l]); |
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305 | printf(", LB: %.3f\n", ComputeLoadImbalance(ncon, 2, npwgts, tpwgts)); |
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306 | } |
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307 | |
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308 | graph->mincut = mincut; |
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309 | graph->nbnd = nbnd; |
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310 | |
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311 | for (i=0; i<ncon; i++) { |
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312 | PQueueFree(ctrl, &parts[i][0]); |
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313 | PQueueFree(ctrl, &parts[i][1]); |
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314 | } |
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315 | |
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316 | ASSERT(ComputeCut(graph, where) == graph->mincut); |
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317 | ASSERT(CheckBnd(graph)); |
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318 | |
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319 | idxwspacefree(ctrl, nvtxs); |
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320 | idxwspacefree(ctrl, nvtxs); |
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321 | idxwspacefree(ctrl, nvtxs); |
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322 | } |
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323 | |
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324 | |
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325 | |
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326 | /************************************************************************* |
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327 | * This function selects the partition number and the queue from which |
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328 | * we will move vertices out |
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329 | **************************************************************************/ |
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330 | int SelectQueueOneWay2(int ncon, float *pto, PQueueType queues[MAXNCON][2], float *ubvec) |
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331 | { |
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332 | int i, cnum=-1, imax, maxgain; |
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333 | float max=0.0; |
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334 | float twgt[MAXNCON]; |
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335 | |
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336 | for (i=0; i<ncon; i++) { |
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337 | if (max < pto[i]) { |
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338 | imax = i; |
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339 | max = pto[i]; |
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340 | } |
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341 | } |
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342 | for (i=0; i<ncon; i++) |
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343 | twgt[i] = (max/(ubvec[imax]*ubvec[i]))/pto[i]; |
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344 | twgt[imax] = 0.0; |
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345 | |
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346 | max = 0.0; |
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347 | for (i=0; i<ncon; i++) { |
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348 | if (max < twgt[i] && (PQueueGetSize(&queues[i][0]) > 0 || PQueueGetSize(&queues[i][1]) > 0)) { |
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349 | max = twgt[i]; |
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350 | cnum = i; |
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351 | } |
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352 | } |
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353 | if (max > 1) |
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354 | return cnum; |
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355 | |
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356 | /* optimize of cut */ |
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357 | maxgain = -10000000; |
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358 | for (i=0; i<ncon; i++) { |
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359 | if (PQueueGetSize(&queues[i][0]) > 0 && PQueueGetKey(&queues[i][0]) > maxgain) { |
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360 | maxgain = PQueueGetKey(&queues[i][0]); |
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361 | cnum = i; |
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362 | } |
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363 | } |
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364 | |
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365 | return cnum; |
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366 | |
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367 | } |
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368 | |
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