POJ 2395 Out of Hay（MST）

【题目链接】http://poj.org/problem?id=2395

【解题思路】找最小生成树中权值最大的那条边输出，模板过的，出现了几个问题，开的数据不够大导致运行错误，第一次用模板，理解得不够深厚且模板有错误导致提交错误

 

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<cmath>
 #include<queue>
 #include<algorithm>
 #define INF 1000000002
 #define MAXN 2002
 #define SIZE 20200

 using namespace std;

 int eh[MAXN], tot, dist[MAXN];
 bool visit[MAXN];
 int n, m;
 struct Edge{
     int v, u, cost, next;
     Edge(){}
     Edge(int a, int b, int c, int d){
         v = a, u = b, cost = c, next = d;
     }
     Edge(int a, int b){v = a, cost = b;}
     bool operator < (const Edge &x) const{
         return cost > x.cost;
     }
 };
 struct Edge edge[SIZE];

 int prim(int s)
 {
     for(int i = ; i <= n; ++i) visit[i] = false, dist[i] = INF;
     dist[s] = ;
     priority_queue<Edge> que;
     que.push(Edge(s, ));
     int ans = ;
     while(!que.empty())
     {
         Edge tmp = que.top();
         que.pop();
         int u = tmp.v, cost = tmp.cost;
         if(visit[u]) continue;
         if(cost > ans) ans = cost;
         visit[u] = true;
         for(int i=eh[u]; i != -; i = edge[i].next)
         {
             int v = edge[i].u;
             if(!visit[v] && dist[v] > edge[i].cost)
             {
                 dist[v] = edge[i].cost;
                 que.push(Edge(v, dist[v]));
             }
         }
     }
     return ans;
 }

 void addedge(int a, int b, int c)
 {
     Edge e = Edge(a, b, c, eh[a]);
     edge[tot] = e;
     eh[a] = tot++;
 }

 void init()
 {
     tot = ;
     memset(eh, -, sizeof(eh));
 }

 int main()
 {
     scanf("%d%d", &n, &m);
     init();
     for(int i = ; i <= m; ++i)
     {
         int u, v, cost;
         scanf("%d%d%d", &u, &v, &cost);
         addedge(v, u, cost);
         addedge(u, v, cost);
     }
     printf("%d\n", prim());
     return ;
 }