Submission #747693

#	Time	Username	Problem	Language	Result	Execution time	Memory
747693		1075508020060209tc	Duathlon (APIO18_duathlon)	C++14	0 / 100	1074 ms	1048576 KiB

count_triplets

#include <bits/stdc++.h>

using namespace std;
#define int long long

int n;int m;
vector<int>e[300005];

int sz[300005];
int ans;
void dfssz(int nw,int pa){
sz[nw]=1;
for(int i=0;i<e[nw].size();i++){
    int v=e[nw][i];
    if(v==pa){continue;}
    dfssz(v,nw);
    sz[nw]+=sz[v];
}
}



void dfs(int nw,int pa,int rtsz){
ans+=(rtsz-sz[nw])*(sz[nw]-1);
for(int i=0;i<e[nw].size();i++){
    int v=e[nw][i];
    if(v==pa){continue;}
    dfs(v,nw,rtsz);
    ans+=sz[v]*(rtsz-1-sz[v]);
}
}


signed main()
{
    cin>>n>>m;
    for(int i=1;i<=m;i++){
        int a;int b;
        cin>>a>>b;
        e[a].push_back(b);
        e[b].push_back(a);
    }
    ans=0;
    vector<int>rt;
    for(int i=1;i<=n;i++){
        if(sz[i]==0){
            dfssz(i,0);
            rt.push_back(i);
        }
    }
    for(int i=0;i<1;i++){
        dfs(rt[i],0,sz[rt[i]]);
    }
    cout<<ans<<endl;
}

Compilation message (stderr)

count_triplets.cpp: In function 'void dfssz(long long int, long long int)':
count_triplets.cpp:13:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 | for(int i=0;i<e[nw].size();i++){
      |             ~^~~~~~~~~~~~~
count_triplets.cpp: In function 'void dfs(long long int, long long int, long long int)':
count_triplets.cpp:25:14: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 | for(int i=0;i<e[nw].size();i++){
      |             ~^~~~~~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 8
• Subtask 4: 0 / 10
• Subtask 5: 0 / 13
• Subtask 6: 0 / 15
• Subtask 7: 0 / 20
• Subtask 8: 0 / 8
• Subtask 9: 0 / 10