POJ 3259 Wormholes(SPFA+邻接表)

( ̄▽ ̄)"

#include<iostream>
#include<cstdio>
#include<queue>
#include<vector>
#include<cstring>
#include<algorithm>
using namespace std;

const int INF=10e7;
const int MAXN=510;
int f,n,m,w,s,e,t;
int lc[MAXN],cntNode[MAXN];
bool vis[MAXN];

struct edge
{
    int v,cost;
}E;
vector<edge> Edge[MAXN];

bool SPFA()
{
    queue<int> que;
    int u,v,c,len;

    for(int i=1;i<=n;i++)
        lc[i]=INF,vis[i]=0,cntNode[i]=0;
    lc[1]=0;vis[1]=1;cntNode[1]=1;
    que.push(1);

    while(!que.empty())
    {
        u=que.front();que.pop();
        vis[u]=0;len=Edge[u].size();

        for(int i=0;i<len;i++)
        {
            v=Edge[u][i].v;
            c=Edge[u][i].cost;
            if(lc[v]>lc[u]+c)
            {
                lc[v]=lc[u]+c;
                if(!vis[v])
                {
                    vis[v]=1;
                    ++cntNode[v];
                    que.push(v);
                    if(cntNode[v]>n)
                        return true;
                }
            }
        }
    }
    return false;
}

int main()
{
    scanf("%d",&f);
    while(f--)
    {
        scanf("%d%d%d",&n,&m,&w);
        for(int i=1;i<=n;i++)
            Edge[i].clear();
        while(m--)
        {
            scanf("%d%d%d",&s,&e,&t);
            E.v=e;E.cost=t;
            Edge[s].push_back(E);
            E.v=s;E.cost=t;
            Edge[e].push_back(E);
        }
        while(w--)
        {
            scanf("%d%d%d",&s,&e,&t);
            E.v=e;E.cost=-t;
            Edge[s].push_back(E);
        }
        if(SPFA()) printf("YES
");
        else printf("NO
");
    }
    return 0;
}
原文地址:https://www.cnblogs.com/atmacmer/p/5196914.html