Submission #261571

#	Time	Username	Problem	Language	Result	Execution time	Memory
261571		Rouge_Hugo	Duathlon (APIO18_duathlon)	C++14	0 / 100	124 ms	19456 KiB

count_triplets

#include<bits/stdc++.h>
#define fi first
#define pb push_back
#define ll long long
using namespace std;
int n,m;
ll re=0;
int szz=0;
const int N=200009;
vector<pair<int,int>>v[N];
vector<int>v1[N];
ll cnt=1,num[N],low[N],bridge[N],b[N],par[N],vis[N],sz[N],bo[N],t[N];
void solve(int x,int p)
{
    vis[x]=1;
    for(auto it:v1[x])
    {
        if(it==p)continue;
        solve(it,x);
        sz[x]+=sz[it];
    }
    sz[x]+=1;bo[x]=1;
}
void go (int x,int p,ll up)
{
    vis[x]=1;
    sz[x]-=bo[x];
    /*if(bo[x]>=3)
        re+=bo[x]*(bo[x]-1)*(bo[x]-2);*/
    re+=2*up*bo[x]*sz[x];
    /*if(bo[x]>2)
    {
        re+=(up)*((bo[x])-1)*((bo[x])-2)*2;
        re+=(sz[x])*(bo[x]-1)*(bo[x]-2)*2;
    }
    re+=(bo[x]-1)*up*2;
    re+=(bo[x]-1)*(sz[x])*2;*/
    for(auto it:v1[x])
    {
        if(it==p)continue;
        re+=2*t[x]*sz[it]*bo[x];
        t[x]+=sz[it];
        go(it,x,up+bo[x]+sz[x]-sz[it]);

    }
}
int main()
{
    ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    scanf("%d %d", &n, &m);
    for(int i=0;i<m;i++)
    {
        int x,y;cin>>x>>y;
        v1[x].pb(y);
        v1[y].pb(x);
    }
    cnt=n+1;
    for(int i=1;i<cnt;i++)
    {
        if(vis[i])continue;
        solve(i,0);
    }
    re=0;
    memset (vis,0,sizeof vis);
    for(int i=1;i<cnt;i++)
    {
        if(vis[i])continue;
        go(i,0,0);
    }
    cout<<re;
}

Compilation message (stderr)

count_triplets.cpp: In function 'int main()':
count_triplets.cpp:50:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~

• 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