Submission #3010230

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
class UnionFind {
	vector<int> par;
	vector<int> rank;
	int find(int a) {
		return par[a] < 0 ? a : par[a] = find(par[a]);
	}
public:
	UnionFind(int n) : par(n, -1), rank(n, 1) {}
	bool same(int a, int b) {
		return find(a) == find(b);
	}
	void unite(int a, int b) {
		a = find(a);
		b = find(b);
		if (a == b) return;
		if (rank[a] > rank[b]) {
			par[a] += par[b];
			par[b] = a;
		}
		else {
			par[b] += par[a];
			par[a] = b;
			if (rank[a] == rank[b]) rank[b]++;
		}
	}
	int size(int a) {
		return -par[find(a)];
	}
};

int main()
{
	ll N, M;
	cin >> N >> M;
	UnionFind uf(N);
	for (int i = 0; i < M; i++) {
		int a, b;
		cin >> a >> b; a--; b--;
		uf.unite(a, b);
	}
	ll s1 = min(uf.size(0), uf.size(1)), s2 = N - s1;
	cout << (s1 * (s1 - 1) / 2 + s2 * (s2 - 1) / 2 - M) << endl;
	return 0;
}

Submission Info

Compile Error

./Main.cpp:3:7: error: expected nested-name-specifier before ‘ll’
 using ll = long long;
       ^
./Main.cpp: In function ‘int main()’:
./Main.cpp:36:2: error: ‘ll’ was not declared in this scope
  ll N, M;
  ^
./Main.cpp:37:9: error: ‘N’ was not declared in this scope
  cin >> N >> M;
         ^
./Main.cpp:37:14: error: ‘M’ was not declared in this scope
  cin >> N >> M;
              ^
./Main.cpp:44:5: error: expected ‘;’ before ‘s1’
  ll s1 = min(uf.size(0), uf.size(1)), s2 = N - s1;
     ^
./Main.cpp:45:11: error: ‘s1’ was not declared in this scope
  cout << (s1 * (s1 - 1) / 2 + s2 * (s2 - 1) / 2 - M) << endl;
           ^
./Main.cpp:45:31: error: ‘s2’ was not declared in this scope
  cout << (s1 * (s1 - 1) / 2 + s2 * (s2 - 1) / 2 - M) << endl;
                               ^