poj 1511

点击打开链接//dijkstra,有向图,逆邻接表//vector容器还是挺费时间的#include <iostream>#include<cstdio>#include<vector>#include<cstring>#include<queue>using namespace std;typedef long long LL;typedef pair<LL,LL>PII;const int maxn=1000010;const LL INF=1e10+10;struct Edge{int to;LL weight;Edge(int to,LL weight):to(to),weight(weight) {}};vector<Edge>edges[maxn];int u[maxn],pos[maxn];                                  //反向建图LL cost[maxn];LL d[maxn];bool done[maxn];int v,e;void dijkstra(){    memset(done,false,sizeof(done));    for(int i=1;i<=v;i++)        d[i]=(i==1?0:INF);    priority_queue<PII,vector<PII>,greater<PII> >pq;    pq.push(PII(d[1],1));    while(!pq.empty())    {        PII k=pq.top();        pq.pop();        int v1=k.second;        if(done[v1]) continue;        done[v1]=true;        for(int i=0;i<edges[v1].size();i++)            if(d[edges[v1][i].to]>d[v1]+edges[v1][i].weight) {                d[edges[v1][i].to]=d[v1]+edges[v1][i].weight;                pq.push(PII(d[edges[v1][i].to],edges[v1][i].to));            }    }}int main(){    int T;    scanf("%d",&T);    while(T--)    {        scanf("%d%d",&v,&e);        for(int i=0;i<e;i++)        {            scanf("%d%d%lld",&u[i],&pos[i],&cost[i]);            edges[u[i]].push_back(Edge(pos[i],cost[i]));        }        dijkstra();        LL sum=0;        for(int i=1;i<=v;i++)                {                    sum+=d[i];                    edges[i].clear();                }        //反向建图        for(int i=0;i<e;i++)            edges[pos[i]].push_back(Edge(u[i],cost[i]));        dijkstra();        for(int i=1;i<=v;i++)        {            sum+=d[i];            edges[i].clear();        }        printf("%lld\n",sum);    }    return 0;}