紧急救援

题目详情 - L2-001 紧急救援 (25 分) (pintia.cn)

#include<iostream>
#include<cstring>
#include<queue>
using namespace std;
typedef pair<int,int> PAII;
int n,m,A,B;
const int N=550,M=N*N;
int h[N],e[M],ne[M],w[M],dist[N],pre[N],idx,s[N],cnt[N],sum[N];
bool st[N];
void add(int a,int b,int c)
{
    e[idx]=b;
    w[idx]=c;
    ne[idx]=h[a];
    h[a]=idx++;
}
void dijkstra(){
    priority_queue<PAII,vector<PAII>,greater<PAII> > heap;
    memset(dist,0x3f,sizeof(dist));
    dist[A]=0;
    pre[A]=-1;
    cnt[A]=1;
    sum[A]=s[A];
    heap.push({0,A});//距离和点
    while(heap.size())
    {
        auto t=heap.top();
        heap.pop();
        int dis=t.first,ver=t.second;
        if(st[ver]) continue;
        else st[ver]=true;
        for(int i=h[ver];i!=-1;i=ne[i])
        {
            int j=e[i];
            if(dist[j]>dist[ver]+w[i])
            {
                dist[j]=dist[ver]+w[i];
                cnt[j]=cnt[ver];
                pre[j]=ver;
                sum[j]=sum[ver]+s[j];
                heap.push({dist[j],j});
            }
            else if(dist[j]==dist[ver]+w[i])
            {
                cnt[j]+=cnt[ver];
                if(sum[j]<sum[ver]+s[j])
                {
                    sum[j]=sum[ver]+s[j];
                    pre[j]=ver;
                }
            }
        } 
    } 
}
int main(){
    cin>>n>>m>>A>>B;
    memset(h,-1,sizeof(h));
    for(int i=0;i<n;i++) cin>>s[i];
    while(m--)
    {
        int a,b,c;
        cin>>a>>b>>c;
        add(a,b,c);
        add(b,a,c);
    }
    dijkstra();
    cout<<cnt[B]<<" "<<sum[B]<<endl;
    deque<int> vis;
    int x=B;
    while(x!=-1)
    {
        vis.push_back(x);
        x=pre[x];
    }
    cout<<vis[vis.size()-1];
    for(int i=vis.size()-2;i>=0;i--)
        cout<<" "<<vis[i];
}

标签：cnt,ver,救援,int,sum,紧急,heap,dist
来源： https://www.cnblogs.com/ccwz7/p/16172385.html