提出 #52598181

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ソースコード 拡げる

#include <bits/stdc++.h>

using namespace std;
#define int long long
typedef long double ld;
typedef pair<int, int> pii;
#define all(x) x.begin(), x.end()
#define pb push_back
#define mp make_pair
#define inf 1e15+5
const int mod = 1e9+7;

string printBinary(int n){
	int bits = 0;
	int temp = n;
	string result;
	while(temp != 0){
		bits++;
		temp >>= 1;
	}
	for(int i = bits - 1; i >= 0; i--){
		int k = n >> i;
		if(k&1){
			result += '1';
		}
		else result += '0';;
	}
	return result;
}

int mostSF(int n){
	int k = __builtin_clz(n);
	return (32 - k);
}

int fact(int n){
	int ans = 1;
	for(int i = 1; i <= n; i++) ans *= i;
	return ans;
}

int ncr(int n, int r){
	return fact(n) / fact(r) * fact(n-r);
}

bool is_sorted(vector<int>& a){
	int n = a.size();
	for(int i = 0; i + 1 < n; i++){
		if(a[i] > a[i+1]) return 0;
	}
	return 1;
}

int md(int n){
	if(n < 0){
		return ((n % mod) + mod) % mod;
	}
	return n % mod;
}

const int N = 2e5+10;
vector<int> graph[N];
bool visited[N];
int counter = 0, nn = 0;
int answer = 0;

void dfs(int v){
	visited[v] = 1;
	nn++;
	counter += graph[v].size();
	for(auto c: graph[v]){
		if(!visited[c]){
			dfs(c);
		}
	}
}

signed main(){
	int n, m;
	cin >> n >> m;
	for(int i = 0; i < m; i++){
		int x, y;
		cin >> x >> y;
		graph[x].pb(y);
		graph[y].pb(x);
	}
	for(int i = 1; i <= n; i++){
		if(!visited[i]){
			counter = 0;
			nn = 0;
			dfs(i);
			int should = nn * (nn - 1) / 2;
			answer += (should - counter / 2);
		}
	}
	cout << answer << endl;
}

提出情報

ジャッジ結果