hdu 3790 最短路径问题(最短路)

题目：

        链接：点击打开链接

题意：

思路：

        dijjkstra算法。单源最短路径，更新路径的同时要更新花费。

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
#define INF 10000000

const int N = 1010;

int n,m,a,b,d,c;
int s,t;
int map[N][N],cost[N][N];
int dis[N],val[N];

void dijkstra()
{
    int vis[N];
    memset(vis,0,sizeof(vis));
    for(int i=1; i<=n; i++)
    {
        dis[i] = map[s][i];
        val[i] = cost[s][i];
    }
    for(int i=1; i<n; i++)
    {
        int x,minn = INF;
        for(int y=1; y<=n; y++)
        {
            if(!vis[y] && dis[y] < minn)
            {
                minn = dis[x=y];
            }
        }
        vis[x] = 1;
        for(int y=1; y<=n; y++)
        {
            if(!vis[y] && map[x][y] < INF)
            {
                if(dis[y] > dis[x] + map[x][y])
                {
                    dis[y] = dis[x] + map[x][y];
                    val[y] = val[x] + cost[x][y];
                }
                else if(dis[y] == dis[x] + map[x][y] && (val[y] > val[x] + cost[x][y]))
                {
                    val[y] = val[x] + cost[x][y];
                }
            }
        }
    }
}

int main()
{
    //freopen("input.txt","r",stdin);
    while(scanf("%d%d",&n,&m) != EOF && (n || m))
    {
        for(int i=1; i<=n; i++)
        {
            for(int j=1; j<=n; j++)
            {
                map[i][j] = INF;
                cost[i][j] = INF;
            }
        }
        for(int i=1; i<=m; i++)
        {
            scanf("%d%d%d%d",&a,&b,&c,&d);
            if(map[a][b] > c)
            {
                map[a][b] = map[b][a] = c;
                cost[a][b] = cost[b][a] = d;
            }
            else if(map[a][b] == c && cost[a][b] > d)
            {
                cost[a][b] = cost[b][a] = d;
            }
        }
        scanf("%d%d",&s,&t);
        dijkstra();
        printf("%d %d\n",dis[t],val[t]);
    }
    return 0;
}

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战斗，从不退缩；奋斗，永不停歇~~~~~~~~~~~~~~~~~