hdu3790 最短路径问题

题目地址：http://acm.hdu.edu.cn/showproblem.php?pid=3790

最短路问题，因为结果会超int所以最终结果要用__int64位保存。当距离相等的时候，去费用小的路走。

#include<iostream>
#include<queue>
using namespace std;
#define INF (1<<30)
struct node
{
    int v,d,cost;
    node *next;
}*head[1005],edge[100005*2],*p;
bool vis[1005];
__int64 dis[1005],cost[1005];
int n,m;
void insert(int start,int end,int d,int cost)
{
    p->v = end;
    p->d = d;
    p->cost = cost;
    p->next = head[start];
    head[start] = p++;
}
void spfa(int start)
{
    int i;
    for(i = 1; i <= n; i++)
        dis[i] = cost[i] = INF;
    memset(vis,false,sizeof(vis));
    vis[start] = true;
    dis[start] = 0;
    cost[start] = 0;
    queue<int>Q;
    Q.push(start);
    while(!Q.empty())
    {
        int now = Q.front();
        Q.pop();
        vis[now] = false;
        for(node *p = head[now]; p ; p = p->next)
        {
            if(dis[p->v] > dis[now] + p->d)
            {
                dis[p->v] = dis[now] + p->d;
                cost[p->v] = cost[now]+p->cost;
                if(!vis[p->v])
                {
                    vis[p->v] = true;
                    Q.push(p->v);
                }
            }
            else
                if(dis[p->v] == dis[now] + p->d && cost[p->v] > cost[now] + p->cost)
                {
                    cost[p->v] = cost[now] + p->cost;
                    if( !vis[p->v])
                    {
                        vis[p->v] = true;
                        Q.push(p->v);
                    }
                }
        }
    }
}
int main()
{
    int s,t,i,a,b,d,q;
    while(scanf("%d%d",&n,&m) != EOF && (n || m))
    {
        for(i = 1; i <= n; i++)
            head[i] = NULL;
        p = edge;
        while(m --)
        {
            scanf("%d%d%d%d",&a,&b,&d,&q);
            insert(a,b,d,q);
            insert(b,a,d,q);
        }
        scanf("%d%d",&s,&t);
        spfa(s);
        printf("%I64d %I64d\n",dis[t],cost[t]);
    }
    return 0;
}