hdu-2544-最短路(SPFA模板)

题目链接

题意很清晰，入门级题目，适合各种模板，可用dijkstra, floyd, Bellman-ford, spfa

Dijkstra链接

Floyd链接

Bellman-Ford链接

SPFA链接

 /*
     Name:HDU-2544-最短路
     Copyright:
     Author:
     Date: 2018/4/17 10:34:47
     Description:
     SPFA
 */
 #include <cstring>
 #include <cstdio>
 #include <iostream>
 #include <vector>
 #include <queue>
 #include <utility>
 using namespace std;
 const int MAXN = ;
 int  n, m;
 vector <pair<int, int>> g[MAXN];
 int dist[MAXN];
 bool inQue[MAXN];
 queue<int> que;
 void spfa() {
     memset(inQue, , sizeof(inQue));
     memset(dist, 0x3f, sizeof(dist));
     dist[] = ;
     while (!que.empty()) que.pop();
     que.push();
     inQue[] = true;
     while (!que.empty()) {
         int u = que.front();
         que.pop();
         inQue[u] = false;
         for (int i=; i<g[u].size(); i++) {
             if(dist[u]+g[u][i].second < dist[g[u][i].first]) {
                 dist[g[u][i].first] = dist[u] + g[u][i].second;
                 if (!inQue[g[u][i].first]) {
                     inQue[g[u][i].first] = true;
                     que.push(g[u][i].first);
                 }
             }
         }
     }
 }
 int main()
 {
 //    freopen("in.txt", "r", stdin);
     while (~scanf("%d %d", &n, &m) && (n+m)) {
         for (int i=; i<=; i++) {
             while (!g[i].empty()) {//  while
                 g[i].pop_back();
             }
         }
         for (int i=; i<=m; i++) {
             int a, b, c;
             scanf("%d %d %d", &a, &b, &c);
             g[a].push_back(make_pair(b, c));
             g[b].push_back(make_pair(a, c));
         }
         spfa();
         printf("%d\n", dist[n]);
     }
     return ;
 }