void McRandomBisection(ctrl_t *ctrl, graph_t *graph, real_t *ntpwgts,
idx_t niparts)
{
idx_t i, ii, j, k, nvtxs, ncon, from, bestcut=0, mincut, inbfs, qnum;
idx_t *bestwhere, *where, *perm, *counts;
idx_t *vwgt;
WCOREPUSH;
nvtxs = graph->nvtxs;
ncon = graph->ncon;
vwgt = graph->vwgt;
Allocate2WayPartitionMemory(ctrl, graph);
where = graph->where;
bestwhere = iwspacemalloc(ctrl, nvtxs);
perm = iwspacemalloc(ctrl, nvtxs);
counts = iwspacemalloc(ctrl, ncon);
for (inbfs=0; inbfs<2*niparts; inbfs++) {
irandArrayPermute(nvtxs, perm, nvtxs/2, 1);
iset(ncon, 0, counts);
/* partition by spliting the queues randomly */
for (ii=0; ii<nvtxs; ii++) {
i = perm[ii];
qnum = iargmax(ncon, vwgt+i*ncon);
where[i] = (counts[qnum]++)%2;
}
Compute2WayPartitionParams(ctrl, graph);
FM_2WayRefine(ctrl, graph, ntpwgts, ctrl->niter);
Balance2Way(ctrl, graph, ntpwgts);
FM_2WayRefine(ctrl, graph, ntpwgts, ctrl->niter);
Balance2Way(ctrl, graph, ntpwgts);
FM_2WayRefine(ctrl, graph, ntpwgts, ctrl->niter);
if (inbfs == 0 || bestcut >= graph->mincut) {
bestcut = graph->mincut;
icopy(nvtxs, where, bestwhere);
if (bestcut == 0)
break;
}
}
graph->mincut = bestcut;
icopy(nvtxs, bestwhere, where);
WCOREPOP;
}
void McGrowBisection(ctrl_t *ctrl, graph_t *graph, real_t *ntpwgts,
idx_t niparts)
{
idx_t i, j, k, nvtxs, ncon, from, bestcut=0, mincut, inbfs;
idx_t *bestwhere, *where;
WCOREPUSH;
nvtxs = graph->nvtxs;
Allocate2WayPartitionMemory(ctrl, graph);
where = graph->where;
bestwhere = iwspacemalloc(ctrl, nvtxs);
for (inbfs=0; inbfs<2*niparts; inbfs++) {
iset(nvtxs, 1, where);
where[irandInRange(nvtxs)] = 0;
Compute2WayPartitionParams(ctrl, graph);
Balance2Way(ctrl, graph, ntpwgts);
FM_2WayRefine(ctrl, graph, ntpwgts, ctrl->niter);
Balance2Way(ctrl, graph, ntpwgts);
FM_2WayRefine(ctrl, graph, ntpwgts, ctrl->niter);
if (inbfs == 0 || bestcut >= graph->mincut) {
bestcut = graph->mincut;
icopy(nvtxs, where, bestwhere);
if (bestcut == 0)
break;
}
}
graph->mincut = bestcut;
icopy(nvtxs, bestwhere, where);
WCOREPOP;
}
/*************************************************************************
* This function takes a graph and produces a bisection by using a region
* growing algorithm. The resulting partition is returned in
* graph->where
**************************************************************************/
void GrowBisection(CtrlType *ctrl, GraphType *graph, int *tpwgts, float ubfactor)
{
int i, j, k, nvtxs, drain, nleft, first, last, pwgts[2], minpwgt[2], maxpwgt[2], from, bestcut, icut, mincut, me, pass, nbfs;
idxtype *xadj, *vwgt, *adjncy, *adjwgt, *where;
idxtype *queue, *touched, *gain, *bestwhere;
nvtxs = graph->nvtxs;
xadj = graph->xadj;
vwgt = graph->vwgt;
adjncy = graph->adjncy;
adjwgt = graph->adjwgt;
Allocate2WayPartitionMemory(ctrl, graph);
where = graph->where;
bestwhere = idxmalloc(nvtxs, "BisectGraph: bestwhere");
queue = idxmalloc(nvtxs, "BisectGraph: queue");
touched = idxmalloc(nvtxs, "BisectGraph: touched");
ASSERTP(tpwgts[0]+tpwgts[1] == idxsum(nvtxs, vwgt), ("%d %d\n", tpwgts[0]+tpwgts[1], idxsum(nvtxs, vwgt)));
maxpwgt[0] = ubfactor*tpwgts[0];
maxpwgt[1] = ubfactor*tpwgts[1];
minpwgt[0] = (1.0/ubfactor)*tpwgts[0];
minpwgt[1] = (1.0/ubfactor)*tpwgts[1];
nbfs = (nvtxs <= ctrl->CoarsenTo ? SMALLNIPARTS : LARGENIPARTS);
bestcut = idxsum(nvtxs, graph->adjwgtsum)+1; /* The +1 is for the 0 edges case */
for (; nbfs>0; nbfs--) {
idxset(nvtxs, 0, touched);
pwgts[1] = tpwgts[0]+tpwgts[1];
pwgts[0] = 0;
idxset(nvtxs, 1, where);
queue[0] = RandomInRange(nvtxs);
touched[queue[0]] = 1;
first = 0; last = 1;
nleft = nvtxs-1;
drain = 0;
/* Start the BFS from queue to get a partition */
for (;;) {
if (first == last) { /* Empty. Disconnected graph! */
if (nleft == 0 || drain)
break;
k = RandomInRange(nleft);
for (i=0; i<nvtxs; i++) {
if (touched[i] == 0) {
if (k == 0)
break;
else
k--;
}
}
queue[0] = i;
touched[i] = 1;
first = 0; last = 1;;
nleft--;
}
i = queue[first++];
if (pwgts[0] > 0 && pwgts[1]-vwgt[i] < minpwgt[1]) {
drain = 1;
continue;
}
where[i] = 0;
INC_DEC(pwgts[0], pwgts[1], vwgt[i]);
if (pwgts[1] <= maxpwgt[1])
break;
drain = 0;
for (j=xadj[i]; j<xadj[i+1]; j++) {
k = adjncy[j];
if (touched[k] == 0) {
queue[last++] = k;
touched[k] = 1;
nleft--;
}
}
}
/* Check to see if we hit any bad limiting cases */
if (pwgts[1] == 0) {
i = RandomInRange(nvtxs);
where[i] = 1;
INC_DEC(pwgts[1], pwgts[0], vwgt[i]);
}
/*************************************************************
* Do some partition refinement
**************************************************************/
Compute2WayPartitionParams(ctrl, graph);
/*printf("IPART: %3d [%5d %5d] [%5d %5d] %5d\n", graph->nvtxs, pwgts[0], pwgts[1], graph->pwgts[0], graph->pwgts[1], graph->mincut); */
Balance2Way(ctrl, graph, tpwgts, ubfactor);
/*printf("BPART: [%5d %5d] %5d\n", graph->pwgts[0], graph->pwgts[1], graph->mincut);*/
FM_2WayEdgeRefine(ctrl, graph, tpwgts, 4);
/*printf("RPART: [%5d %5d] %5d\n", graph->pwgts[0], graph->pwgts[1], graph->mincut);*/
if (bestcut > graph->mincut) {
bestcut = graph->mincut;
idxcopy(nvtxs, where, bestwhere);
if (bestcut == 0)
break;
}
}
graph->mincut = bestcut;
idxcopy(nvtxs, bestwhere, where);
GKfree(&bestwhere, &queue, &touched, LTERM);
}
/*************************************************************************
* This function takes a graph and produces a bisection by using a region
* growing algorithm. The resulting partition is returned in
* graph->where
**************************************************************************/
void RandomBisection(CtrlType *ctrl, GraphType *graph, int *tpwgts, float ubfactor)
{
int i, ii, j, k, nvtxs, pwgts[2], minpwgt[2], maxpwgt[2], from, bestcut, icut, mincut, me, pass, nbfs;
idxtype *xadj, *vwgt, *adjncy, *adjwgt, *where;
idxtype *perm, *bestwhere;
nvtxs = graph->nvtxs;
xadj = graph->xadj;
vwgt = graph->vwgt;
adjncy = graph->adjncy;
adjwgt = graph->adjwgt;
Allocate2WayPartitionMemory(ctrl, graph);
where = graph->where;
bestwhere = idxmalloc(nvtxs, "BisectGraph: bestwhere");
perm = idxmalloc(nvtxs, "BisectGraph: queue");
ASSERTP(tpwgts[0]+tpwgts[1] == idxsum(nvtxs, vwgt), ("%d %d\n", tpwgts[0]+tpwgts[1], idxsum(nvtxs, vwgt)));
maxpwgt[0] = ubfactor*tpwgts[0];
maxpwgt[1] = ubfactor*tpwgts[1];
minpwgt[0] = (1.0/ubfactor)*tpwgts[0];
minpwgt[1] = (1.0/ubfactor)*tpwgts[1];
nbfs = (nvtxs <= ctrl->CoarsenTo ? SMALLNIPARTS : LARGENIPARTS);
bestcut = idxsum(nvtxs, graph->adjwgtsum)+1; /* The +1 is for the 0 edges case */
for (; nbfs>0; nbfs--) {
RandomPermute(nvtxs, perm, 1);
idxset(nvtxs, 1, where);
pwgts[1] = tpwgts[0]+tpwgts[1];
pwgts[0] = 0;
if (nbfs != 1) {
for (ii=0; ii<nvtxs; ii++) {
i = perm[ii];
if (pwgts[0]+vwgt[i] < maxpwgt[0]) {
where[i] = 0;
pwgts[0] += vwgt[i];
pwgts[1] -= vwgt[i];
if (pwgts[0] > minpwgt[0])
break;
}
}
}
/*************************************************************
* Do some partition refinement
**************************************************************/
Compute2WayPartitionParams(ctrl, graph);
/* printf("IPART: %3d [%5d %5d] [%5d %5d] %5d\n", graph->nvtxs, pwgts[0], pwgts[1], graph->pwgts[0], graph->pwgts[1], graph->mincut); */
Balance2Way(ctrl, graph, tpwgts, ubfactor);
/* printf("BPART: [%5d %5d] %5d\n", graph->pwgts[0], graph->pwgts[1], graph->mincut); */
FM_2WayEdgeRefine(ctrl, graph, tpwgts, 4);
/* printf("RPART: [%5d %5d] %5d\n", graph->pwgts[0], graph->pwgts[1], graph->mincut); */
if (bestcut > graph->mincut) {
bestcut = graph->mincut;
idxcopy(nvtxs, where, bestwhere);
if (bestcut == 0)
break;
}
}
graph->mincut = bestcut;
idxcopy(nvtxs, bestwhere, where);
GKfree(&bestwhere, &perm, LTERM);
}
/*************************************************************************
* This function projects a partition, and at the same time computes the
* parameters for refinement.
**************************************************************************/
void Project2WayPartition(CtrlType *ctrl, GraphType *graph)
{
int i, j, k, nvtxs, nbnd, me;
idxtype *xadj, *adjncy, *adjwgt, *adjwgtsum;
idxtype *cmap, *where, *id, *ed, *bndptr, *bndind;
idxtype *cwhere, *cid, *ced, *cbndptr;
GraphType *cgraph;
cgraph = graph->coarser;
cwhere = cgraph->where;
cid = cgraph->id;
ced = cgraph->ed;
cbndptr = cgraph->bndptr;
nvtxs = graph->nvtxs;
cmap = graph->cmap;
xadj = graph->xadj;
adjncy = graph->adjncy;
adjwgt = graph->adjwgt;
adjwgtsum = graph->adjwgtsum;
Allocate2WayPartitionMemory(ctrl, graph);
where = graph->where;
id = idxset(nvtxs, 0, graph->id);
ed = idxset(nvtxs, 0, graph->ed);
bndptr = idxset(nvtxs, -1, graph->bndptr);
bndind = graph->bndind;
/* Go through and project partition and compute id/ed for the nodes */
for (i=0; i<nvtxs; i++) {
k = cmap[i];
where[i] = cwhere[k];
cmap[i] = cbndptr[k];
}
for (nbnd=0, i=0; i<nvtxs; i++) {
me = where[i];
id[i] = adjwgtsum[i];
if (xadj[i] == xadj[i+1]) {
bndptr[i] = nbnd;
bndind[nbnd++] = i;
}
else {
if (cmap[i] != -1) { /* If it is an interface node. Note that cmap[i] = cbndptr[cmap[i]] */
for (j=xadj[i]; j<xadj[i+1]; j++) {
if (me != where[adjncy[j]])
ed[i] += adjwgt[j];
}
id[i] -= ed[i];
if (ed[i] > 0 || xadj[i] == xadj[i+1]) {
bndptr[i] = nbnd;
bndind[nbnd++] = i;
}
}
}
}
graph->mincut = cgraph->mincut;
graph->nbnd = nbnd;
idxcopy(2, cgraph->pwgts, graph->pwgts);
FreeGraph(graph->coarser);
graph->coarser = NULL;
}
void GrowBisection(ctrl_t *ctrl, graph_t *graph, real_t *ntpwgts,
idx_t niparts)
{
idx_t i, j, k, nvtxs, drain, nleft, first, last,
pwgts[2], oneminpwgt, onemaxpwgt,
from, me, bestcut=0, icut, mincut, inbfs;
idx_t *xadj, *vwgt, *adjncy, *where;
idx_t *queue, *touched, *gain, *bestwhere;
WCOREPUSH;
nvtxs = graph->nvtxs;
xadj = graph->xadj;
vwgt = graph->vwgt;
adjncy = graph->adjncy;
// adjwgt = graph->adjwgt;
Allocate2WayPartitionMemory(ctrl, graph);
where = graph->where;
bestwhere = iwspacemalloc(ctrl, nvtxs);
queue = iwspacemalloc(ctrl, nvtxs);
touched = iwspacemalloc(ctrl, nvtxs);
onemaxpwgt = ctrl->ubfactors[0]*graph->tvwgt[0]*ntpwgts[1];
oneminpwgt = (1.0/ctrl->ubfactors[0])*graph->tvwgt[0]*ntpwgts[1];
for (inbfs=0; inbfs<niparts; inbfs++) {
iset(nvtxs, 1, where);
iset(nvtxs, 0, touched);
pwgts[1] = graph->tvwgt[0];
pwgts[0] = 0;
queue[0] = irandInRange(nvtxs);
touched[queue[0]] = 1;
first = 0;
last = 1;
nleft = nvtxs-1;
drain = 0;
/* Start the BFS from queue to get a partition */
for (;;) {
if (first == last) { /* Empty. Disconnected graph! */
if (nleft == 0 || drain)
break;
k = irandInRange(nleft);
for (i=0; i<nvtxs; i++) {
if (touched[i] == 0) {
if (k == 0)
break;
else
k--;
}
}
queue[0] = i;
touched[i] = 1;
first = 0;
last = 1;
nleft--;
}
i = queue[first++];
if (pwgts[0] > 0 && pwgts[1]-vwgt[i] < oneminpwgt) {
drain = 1;
continue;
}
where[i] = 0;
INC_DEC(pwgts[0], pwgts[1], vwgt[i]);
if (pwgts[1] <= onemaxpwgt)
break;
drain = 0;
for (j=xadj[i]; j<xadj[i+1]; j++) {
k = adjncy[j];
if (touched[k] == 0) {
queue[last++] = k;
touched[k] = 1;
nleft--;
}
}
}
/* Check to see if we hit any bad limiting cases */
if (pwgts[1] == 0)
where[irandInRange(nvtxs)] = 1;
if (pwgts[0] == 0)
where[irandInRange(nvtxs)] = 0;
/*************************************************************
* Do some partition refinement
**************************************************************/
Compute2WayPartitionParams(ctrl, graph);
/*
printf("IPART: %3"PRIDX" [%5"PRIDX" %5"PRIDX"] [%5"PRIDX" %5"PRIDX"] %5"PRIDX"\n",
graph->nvtxs, pwgts[0], pwgts[1], graph->pwgts[0], graph->pwgts[1], graph->mincut);
*/
Balance2Way(ctrl, graph, ntpwgts);
/*
printf("BPART: [%5"PRIDX" %5"PRIDX"] %5"PRIDX"\n", graph->pwgts[0],
graph->pwgts[1], graph->mincut);
*/
FM_2WayRefine(ctrl, graph, ntpwgts, ctrl->niter);
/*
printf("RPART: [%5"PRIDX" %5"PRIDX"] %5"PRIDX"\n", graph->pwgts[0],
graph->pwgts[1], graph->mincut);
*/
if (inbfs == 0 || bestcut > graph->mincut) {
bestcut = graph->mincut;
icopy(nvtxs, where, bestwhere);
if (bestcut == 0)
break;
}
}
graph->mincut = bestcut;
icopy(nvtxs, bestwhere, where);
WCOREPOP;
}
void RandomBisection(ctrl_t *ctrl, graph_t *graph, real_t *ntpwgts,
idx_t niparts)
{
idx_t i, ii, j, k, nvtxs, pwgts[2], zeromaxpwgt, from, me,
bestcut=0, icut, mincut, inbfs;
idx_t *vwgt, *where;
idx_t *perm, *bestwhere;
WCOREPUSH;
nvtxs = graph->nvtxs;
// xadj = graph->xadj;
vwgt = graph->vwgt;
// adjncy = graph->adjncy;
// adjwgt = graph->adjwgt;
Allocate2WayPartitionMemory(ctrl, graph);
where = graph->where;
bestwhere = iwspacemalloc(ctrl, nvtxs);
perm = iwspacemalloc(ctrl, nvtxs);
zeromaxpwgt = ctrl->ubfactors[0]*graph->tvwgt[0]*ntpwgts[0];
for (inbfs=0; inbfs<niparts; inbfs++) {
iset(nvtxs, 1, where);
if (inbfs > 0) {
irandArrayPermute(nvtxs, perm, nvtxs/2, 1);
pwgts[1] = graph->tvwgt[0];
pwgts[0] = 0;
for (ii=0; ii<nvtxs; ii++) {
i = perm[ii];
if (pwgts[0]+vwgt[i] < zeromaxpwgt) {
where[i] = 0;
pwgts[0] += vwgt[i];
pwgts[1] -= vwgt[i];
if (pwgts[0] > zeromaxpwgt)
break;
}
}
}
/* Do some partition refinement */
Compute2WayPartitionParams(ctrl, graph);
/* printf("IPART: %3"PRIDX" [%5"PRIDX" %5"PRIDX"] [%5"PRIDX" %5"PRIDX"] %5"PRIDX"\n", graph->nvtxs, pwgts[0], pwgts[1], graph->pwgts[0], graph->pwgts[1], graph->mincut); */
Balance2Way(ctrl, graph, ntpwgts);
/* printf("BPART: [%5"PRIDX" %5"PRIDX"] %5"PRIDX"\n", graph->pwgts[0], graph->pwgts[1], graph->mincut); */
FM_2WayRefine(ctrl, graph, ntpwgts, 4);
/* printf("RPART: [%5"PRIDX" %5"PRIDX"] %5"PRIDX"\n", graph->pwgts[0], graph->pwgts[1], graph->mincut); */
if (inbfs==0 || bestcut > graph->mincut) {
bestcut = graph->mincut;
icopy(nvtxs, where, bestwhere);
if (bestcut == 0)
break;
}
}
graph->mincut = bestcut;
icopy(nvtxs, bestwhere, where);
WCOREPOP;
}
void Project2WayPartition(ctrl_t *ctrl, graph_t *graph)
{
idx_t i, j, istart, iend, nvtxs, nbnd, me, tid, ted;
idx_t *xadj, *adjncy, *adjwgt;
idx_t *cmap, *where, *bndptr, *bndind;
idx_t *cwhere, *cbndptr;
idx_t *id, *ed;
graph_t *cgraph;
Allocate2WayPartitionMemory(ctrl, graph);
cgraph = graph->coarser;
cwhere = cgraph->where;
cbndptr = cgraph->bndptr;
nvtxs = graph->nvtxs;
cmap = graph->cmap;
xadj = graph->xadj;
adjncy = graph->adjncy;
adjwgt = graph->adjwgt;
where = graph->where;
id = graph->id;
ed = graph->ed;
bndptr = iset(nvtxs, -1, graph->bndptr);
bndind = graph->bndind;
/* Project the partition and record which of these nodes came from the
coarser boundary */
for (i=0; i<nvtxs; i++) {
j = cmap[i];
where[i] = cwhere[j];
cmap[i] = cbndptr[j];
}
/* Compute the refinement information of the nodes */
for (nbnd=0, i=0; i<nvtxs; i++) {
istart = xadj[i];
iend = xadj[i+1];
tid = ted = 0;
if (cmap[i] == -1) { /* Interior node. Note that cmap[i] = cbndptr[cmap[i]] */
for (j=istart; j<iend; j++)
tid += adjwgt[j];
}
else { /* Potentially an interface node */
me = where[i];
for (j=istart; j<iend; j++) {
if (me == where[adjncy[j]])
tid += adjwgt[j];
else
ted += adjwgt[j];
}
}
id[i] = tid;
ed[i] = ted;
if (ted > 0 || istart == iend)
BNDInsert(nbnd, bndind, bndptr, i);
}
graph->mincut = cgraph->mincut;
graph->nbnd = nbnd;
/* copy pwgts */
icopy(2*graph->ncon, cgraph->pwgts, graph->pwgts);
FreeGraph(&graph->coarser);
graph->coarser = NULL;
}
