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# qnighy/rmq_ijk.cpp

Created February 17, 2011 13:10
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As priority_queue broken, we tried implementing Dijkstra using RMQ.
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 #include #include #include #include using namespace std; int main() { while(true) { int n,m; scanf("%d%d", &n, &m); if(m==0) break; vector > > > graph; graph.resize(m); for(int i = 0; i < n; i++) { int a,b,c,t; scanf("%d%d%d%d", &a, &b, &c, &t); a--; b--; graph[a].push_back(make_pair(b,make_pair(c,t))); graph[b].push_back(make_pair(a,make_pair(c,t))); } int k; scanf("%d", &k); for(int ii = 0; ii < k; ii++) { int p,q,r; scanf("%d%d%d", &p, &q, &r); p--; q--; const int INIT = INT_MAX/2; const int FIN = INT_MAX/2-1; static int segt[1<<8]; fill(segt, segt+(1<<8), INIT); segt[p+(1<<7)] = 0; for(int j = p+(1<<7); j > 1; j>>=1) segt[j>>1] = min(segt[j],segt[j^1]); while(segt[1] < FIN) { int j; for(j = 1; j < (1<<7);) if(segt[j*2] 1; j>>=1) segt[j>>1] = min(segt[j],segt[j^1]); if(cur == q) { printf("%d\n", curcost); break; } for(int i = 0; i < (int)graph[cur].size(); i++) { int to = graph[cur][i].first; int ecost = graph[cur][i].second.first; if(r==1) ecost = graph[cur][i].second.second; if(segt[to+(1<<7)] != FIN && segt[to+(1<<7)] > curcost+ecost) { segt[to+(1<<7)] = curcost+ecost; for(j = to+(1<<7); j > 1; j>>=1) segt[j>>1] = min(segt[j],segt[j^1]); } } } } } return 0; }