제출 #552408

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
552408		zaneyu	철인 이종 경기 (APIO18_duathlon)	C++14	25 / 100	1096 ms	20636 KiB

count_triplets

/*input
4 4
1 2
2 3
3 4
4 2
*/
#include<bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0;i<n;i++)
const int maxn=1e5+5;
#define pb push_back
#define lowb(x) x&(-x)
#define ll long long
#define MNTO(x,y) x=min(x,y)
#define REP1(i,n) for(int i=1;i<=n;i++)
vector<int> v[maxn];
int vis[maxn];
int dep[maxn],low[maxn];
ll ans=0;
int sz[maxn];
int par[maxn][10];
void dfs(int u,int p){
    low[u]=dep[u];
    vis[u]=1;
    sz[u]=1;
    par[u][0]=p;
    REP1(j,9){
        if(par[u][j-1]==-1) par[u][j]=-1;
        else par[u][j]=par[par[u][j-1]][j-1];
    }
    for(int x:v[u]){
        if(x==p) continue;
        if(!vis[x]){
            dep[x]=dep[u]+1;
            dfs(x,u);
            sz[u]+=sz[x];
            MNTO(low[u],low[x]);
        }
        else{
            MNTO(low[u],low[x]);
        }
    }
    if(dep[u]>1) ans+=dep[u]-1;
}
void dfs2(int u,int p){
    vis[u]=2;
    for(int x:v[u]){
        if(x==p) continue;
        if(vis[x]==1){
            dfs2(x,u);
        }
    }
    if(dep[u]-low[u]>1){
        int k=dep[u]-low[u]-1;
        int x=u;
        while(k){
            x=par[x][__lg(lowb(k))];
            k-=lowb(k);
        }
        ans+=sz[x]-sz[u];
    }
}
int main(){
    ios::sync_with_stdio(false),cin.tie(0);
    int n,m;
    cin>>n>>m;
    REP(i,m){
        int a,b;
        cin>>a>>b;
        --a,--b;
        v[a].pb(b),v[b].pb(a);
    }
    REP(i,n){
        REP(j,n) vis[j]=0;
        dep[i]=0;
        dfs(i,-1);
        dfs2(i,-1);
        //cout<<ans<<' ';
    }
    cout<<ans<<'\n';
}

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