DAG最短路算法

来源：互联网发布：写真机软件编辑：程序博客网时间：2024/06/06 19:04
#include <cstdio>#include <iostream>#include <queue>#include <vector>#include <stack>using namespace std;#define INF 1000000int d[100];  queue<int> que; vector<int> vec[1000];vector<int> w[1000];int n,m;int F[1000];int topu_rudu(){      stack<int> st;      for(int i = 0;i < n;i++){          d[i] = vec[i].size();          if(d[i] == 0){              st.push(i);          }      }      while(!st.empty()){          int u = st.top();          st.pop();          que.push(u);              int si = vec[u].size();          for(int i = 0;i < si;i++){              int v = vec[u][i];              d[v]--;              if(d[v] == 0){                  st.push(v);              }          }      }  }int DAG_SHORTEST_PATHS(){topu_rudu();for(int i = 0;i < n;i++){d[i] = INF;F[i] = -1; }while(!que.empty()){int u = que.front();que.pop();int si = vec[u].size();for(int i = 0;i < si;i++){int v = vec[u][i];if(d[v] > d[u] + w[u][i]){d[v] = d[u] + w[u][i];F[v] = u;}}}}int main(){while(cin >> n >> m){for(int i = 0;i < m;i++){int x,y,v;cin >> x >> y>> v;w[x].push_back(y);vec[x].push_back(v);}DAG_SHORTEST_PATHS();} return 0;}
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