POJ 1724 ROADS

题目链接

题意：找花费不超过k的最短路。

分析：dijkstra+优先队列+bfs

#include
#include
#include
#include
#include
#include
#include
#define MAX_V 105
#define inf 1000000000
using namespace std;
struct edge
{
    int to,cost,toll;
    edge(){}
    edge(int to,int cost,int toll):to(to),cost(cost),toll(toll){}
};
struct P
{
    int first;
    int second;
    int third;
    P(int first,int second,int third):first(first),second(second),third(third){}
    bool operator<(const P &other)const
    {
        return first>other.first;
    }
};
int V;
vectorG[MAX_V];
int k,r;
int tol;
int dijkstra(int s)
{
    priority_queue
que;
    que.push(P(0,s,0));
    while(!que.empty())
    {
        P p=que.top();
        que.pop();
        int v=p.second;
        if(v==V)
        return p.first;
        for(int i=0;iif(p.third+e.toll<=k)
            que.push(P(p.first+e.cost,e.to,p.third+e.toll));
        }
    }
    return -1;
}
int main(void)
{
    while(scanf("%d%d%d",&k,&V,&r)==3)
    {
        for(int i=0;iint s,e,l,t;
            scanf("%d%d%d%d",&s,&e,&l,&t);
            G[s].push_back(edge(e,l,t));
//          G[e].push_back(edge(s,l,t));
        }
        tol=0;
        printf("%d\n",dijkstra(1));
    }
    return 0;
}