# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
4000 | 2013-08-31T09:55:52 Z | Qwaz | Following Flow (kriii1_F) | C++ | 0 ms | 0 KB |
#include <cstdio> #include <vector> #include <queue> const int N_MAX=35, M_MAX=1020; struct state { int time, node; double ratio; bool operator < (const state &t) const { return time*ratio > t.time*t.ratio; } }; struct edge { int to, time; }; int n, m, outCount[N_MAX]; std::vector < edge > to[N_MAX]; void input(){ scanf("%d%d", &n, &m); int i; for(i=0; i<m; i++){ int p, q, r; scanf("%d%d%d", &p, &q, &r); edge t; t.time = r; t.to = q; to[p].push_back(t); } } std::priority_queue < state > pq; double res; void solve(){ state now; now.node = 0; now.ratio = 1; now.time = 0; pq.push(now); while(true){ now = pq.top(); pq.pop(); if(now.ratio < DBL_EPSILON) break; int i, size=to[now.node].size(); for(i=0; i<size; i++){ int next = to[now.node][i].to; int edgeTime = to[now.node][i].time; state sNext; sNext.node = next; sNext.ratio = now.ratio/size; sNext.time = now.time+edgeTime; if(next == n) res += sNext.ratio*sNext.time; else pq.push(sNext); } } printf("%.10lf\n", res); } int main(){ input(); solve(); return 0; }