显示代码纯文本
#include<bits/stdc++.h>
#define ll long long
#define N 3001
using namespace std;
int n,m;
ll ans,dis[N],vis[N];
vector<pair<ll,ll>> g[N];
priority_queue<pair<ll,ll>> q;
struct node{
int u,v,l,c;
bool operator<(const node &x)const{
if(l!=x.l) return l<x.l;
return c<x.c;
}
}a[N];
int f(int s,int t){
for(int i=1;i<=n;i++){
dis[i]=2e9;
vis[i]=0;
}
dis[s]=0;
q.push({0,s});
while(!q.empty()){
int u=q.top().second;
q.pop();
if(vis[u]) continue;
vis[u]=1;
for(auto &e:g[u]){
int v=e.first,w=e.second;
if(dis[v]>dis[u]+w){
dis[v]=dis[u]+w;
q.push({-dis[v],v});
}
}
}
return dis[t];
}
int main(){
freopen("Roads.in","r",stdin);
freopen("Roads.out","w",stdout);
ios::sync_with_stdio(false);
cin.tie(0);
cin>>n>>m;
for(int i=1;i<=m;i++) cin>>a[i].u>>a[i].v>>a[i].l>>a[i].c;
sort(a+1,a+m+1);
for(int i=1;i<=m;i++)
if(f(a[i].u,a[i].v)>a[i].l){
ans+=a[i].c;
g[a[i].u].push_back({a[i].v,a[i].l});
g[a[i].v].push_back({a[i].u,a[i].l});
}
cout<<ans<<endl;
return 0;
}