This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include<bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define int long long
using namespace std;
const int N=1e6,M=2e3,mod=1e9+7;
int n,up[N][30],innode[N],outnode[N],timee=0,val[N],val2[N];
map<pair<int,int>,int>mpp;
vector<int>adj[N];
vector<pair<int,int>>v;
void dfs(int node,int par){
    innode[node]=timee++;
    up[node][0]=par;
    for(int j=1;j<ceil(log2(n));j++)
        up[node][j]=up[up[node][j-1]][j-1];
    for(auto x:adj[node]){
        if(x==par)
            continue;
        dfs(x,node);
    }
    outnode[node]=timee++;
}
bool is_parent(int x,int y){
    return innode[x]<=innode[y]&&outnode[x]>=outnode[y];
}
int lca(int x,int y){
    if(is_parent(x,y))
        return x;
    if(is_parent(y,x))
        return y;
    for(int i=ceil(log2(n))+1;i>=0;i--){
        if(!is_parent(up[x][i],y))
            x=up[x][i];
    }
    return up[x][0];
}
void dfs2(int node,int par){
    for(auto x:adj[node]){
        if(x==par)
            continue;
        dfs2(x,node);
        val2[node]+=val2[x];
        mpp[{node,x}]=val2[x];
        mpp[{x,node}]=val2[x];
    }
    val2[node]+=val[node];
}
main()
{
    cin>>n;
    map<pair<int,int>,pair<int,int>>mp;
    for(int i=0;i<n-1;i++){
        int x,y,cost1,cost2;
        cin>>x>>y>>cost1>>cost2;
        v.pb({x,y});
        mp[{x,y}]={cost1,cost2};
        adj[x].pb(y);
        adj[y].pb(x);
    }
    dfs(1,0);
    innode[0]=-1;
    outnode[0]=++timee;
    for(int i=2;i<=n;i++){
        int lcaa=lca(i,i-1);
        val[i]++;
        val[i-1]++;
        val[lcaa]-=2;
    }
    dfs2(1,0);
    int ans=0;
    for(int i=0;i<v.size();i++){
        int cost1=mp[{v[i].F,v[i].S}].F*mpp[{v[i].F,v[i].S}];
        int cost2=mp[{v[i].F,v[i].S}].S;
        ans+=min(cost1,cost2);
    }
    cout<<ans<<endl;
    return 0;
}
Compilation message (stderr)
putovanje.cpp:74:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   74 | main()
      | ^~~~
putovanje.cpp: In function 'int main()':
putovanje.cpp:112:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  112 |     for(int i=0;i<v.size();i++){
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