1450. Russian Pipelines（ｓｐｆａ）

１４５０

水题　最长路

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 #include<queue>
 #include<vector>
 using namespace std;
 int n,m;
 vector<int>ed[];
 int vis[],dis[],w[][];
 void spfa(int s,int e)
 {
     int i;
     queue<int>q;
     q.push(s);
     vis[s] = ;
     while(!q.empty())
     {
         int u = q.front();
         q.pop();
         vis[u] = ;
         for(i =  ; i < (int)ed[u].size() ; i++)
         {
             int v = ed[u][i];
             if(dis[v]<dis[u]+w[u][v])
             {
                 dis[v] = dis[u]+w[u][v];
                 if(!vis[v])
                 {
                     vis[v] = ;
                     q.push(v);
                 }
             }
         }
     }
     if(dis[e])
     printf("%d\n",dis[e]);
     else
     printf("No solution\n");
 }
 int main()
 {
     int i;
     scanf("%d%d",&n,&m);
     for(i = ; i <= m; i++)
     {
         int u,v,c;
         scanf("%d%d%d",&u,&v,&c);
         w[u][v] = c;
         ed[u].push_back(v);
     }
     int s,e;
     scanf("%d%d",&s,&e);
     spfa(s,e);
     return ;
 }