Submission #106374

#	Time	Username	Problem	Language	Result	Execution time	Memory
106374		Hideo	Duathlon (APIO18_duathlon)	C++14	23 / 100	205 ms	15480 KiB

count_triplets

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define mk make_pair
#define pb push_back
#define fr first
#define sc second
#define vi vector < int >
#define pii pair < int, int >

const int N = 2e5 + 7;
const int INF = 1e9 + 7;

int sz[N];
int n, m;
int ans;

vi g[N];
int asd;
int as[N];

void dfs (int v = 1, int p = 0){
    sz[v] = 1;
    as[v] = asd;
    for (int to : g[v]){
        if (!sz[to]){
            dfs(to, v);
            sz[v] += sz[to];
        }
    }
}

main(){
    cin >> n >> m;
    for (int i = 1; i <= m; i++){
        int a, b;
        scanf("%lld%lld", &a, &b);
        g[a].pb(b);
        g[b].pb(a);
    }
    for (int i = 1; i <= n; i++) {
			if (!sz[i]) {
				asd = i;
				dfs(i);
				ans -= sz[i] * (sz[i] - 1) / 2;
			}
    }
    for (int i = 1; i <= n; i++) {
			ans += (sz[i] * (sz[as[i]] - sz[i]));
    }
    cout << ans * 2;
}

Compilation message (stderr)

count_triplets.cpp:34:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
count_triplets.cpp: In function 'int main()':
count_triplets.cpp:38:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld%lld", &a, &b);
         ~~~~~^~~~~~~~~~~~~~~~~~~~

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