Submission #552522

#	Time	Username	Problem	Language	Result	Execution time	Memory
552522		zaneyu	Duathlon (APIO18_duathlon)	C++14	5 / 100	1094 ms	11292 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];
int d;
bool ok[maxn];
bool dfs(int u){
    if(u==d){
        return true;
    }
    vis[u]=1;
    for(int x:v[u]){
        if(!vis[x]){
            ok[u]|=dfs(x);
        }
    }
    vis[u]=0;
    return ok[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){
            if(i==j) continue;
            d=j;
            REP(k,n) vis[k]=ok[k]=0;
            dfs(i);
            REP(k,n) if(k!=i and k!=j and ok[k]) ++ans;
        }
        //cout<<ans<<' ';
    }
    cout<<ans<<'\n';
}

• Subtask 1: 5 / 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