hdu2066最短路径spfa算法对每个点分别判断0ms过

#include<iostream>
#include<vector>
#include<queue>

using namespace std;
const int MAXN=1005;
const int MAX=999999999;
struct edge
{
    int from,to,cost;
};
vector<edge>v[MAXN];
int dist[MAXN];
bool in_queue[MAXN];
void init()
{
    int i=0;
    for(i=0;i<=MAXN-1;i++)
    {
        v[i].clear();
    }
    memset(in_queue,0,sizeof(in_queue));
}
void spfa(int p)
{
    queue<int>q;
    int i=0;
    for(i=0;i<=MAXN-1;i++)
    {
        dist[i]=MAX;
    }
    while(!q.empty())
    {
        q.pop();
    }
    dist[p]=0;
    q.push(p);
    in_queue[p]=1;
    while(!q.empty())
    {
        int cur=q.front();
        int i=0;
        q.pop();
        in_queue[cur]=0;
        for(i=0;i<=int(v[cur].size())-1;i++)
        {
            int cost=v[cur][i].cost+dist[cur];
            int to=v[cur][i].to;
            if(cost<dist[to])
            {
                dist[to]=cost;
                if(!in_queue[to])
                {
                    q.push(to);
                    in_queue[to]=1;
                }
            }
        }
    }
}
int main()
{
    int T,S,D;
    while(cin>>T>>S>>D)
    {
        init();
        while(T--)
        {
            int from,to,cost;
            cin>>from>>to>>cost;
            edge e={from,to,cost};
            v[e.from].push_back(e);
            swap(e.from,e.to);
            v[e.from].push_back(e);
        }
        int i,j;
        int f[MAXN];
        int t[MAXN];
        int min=-1;
        for(i=0;i<=S-1;i++)
        {
            cin>>f[i];
        }
        for(i=0;i<=D-1;i++)
        {
            cin>>t[i];
        }
        for(i=0;i<=S-1;i++)
        {
            memset(in_queue,0,sizeof(in_queue));
            spfa(f[i]);
            for(j=0;j<=D-1;j++)
            {
               // cout<<dist[t[j]]<<endl;
                if(dist[t[j]]<min||min==-1)
                {
                    min=dist[t[j]];
                }
            }
        }
        cout<<min<<endl;
    }
    return 0;
}

  

原文地址:https://www.cnblogs.com/cj695/p/2609743.html