2673-最短路径

最短路径的裸题，用了nlogn的写法，优先队列，好久没写代码了，中间没bug出乎我的意料，以后每天一题不会落下，加油！

代码：

#include<algorithm>
#include<cmath>
#include<queue>
#include<vector>
using namespace std;
struct Node
{
    int to;
    long long  len;
    bool  operator<(const Node &a) const
    {
        return len  > a.len;
    }
};
bool isUsed[510];
long long ans[510];
vector<Node> NodeQueue[510];
void addEdge(int s, int e, int len)
{
    NodeQueue[s].push_back((Node){e,len});
    NodeQueue[e].push_back((Node){s,len});
}
int n,m;
priority_queue<Node> PriNodeQueue;
int main()
{
    scanf("%d%d", &n, &m);
    while(m--)
    {
        int s, e, len;
        scanf("%d%d%d",&s, &e, &len);
        if(s != e)
            addEdge(s, e, len);
    }
    int s, t;
    scanf("%d%d", &s, &t);
    for(int i = 0; i < 505; i++)
        ans[i] = 999999999999;
    ans[s] = 0;
    PriNodeQueue.push((Node){s,0});
    while(!PriNodeQueue.empty()){
        Node now = PriNodeQueue.top();
        PriNodeQueue.pop();
        int u = now.to;
        if(!isUsed[u]){
            isUsed[u] = true;
            for(int i = 0; i < NodeQueue[u].size(); i++){
                if(!isUsed[NodeQueue[u][i].to]){
                    int v = NodeQueue[u][i].to;
                    int len = NodeQueue[u][i].len;
                    if(ans[v] > ans[u] + len)
                    {
                        ans[v] = ans[u] + len;
                        PriNodeQueue.push((Node){v,ans[v]});
                    }
                }
            }
        }
    }
    printf("%lld",ans[t]);
    return 0;
    
}