oj.uz

답안 #20084

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
20084 2016-02-25T10:46:04 Z hongjun7 트리 (kriii4_X) C++14
0 / 100
 0 ms 1212 KB 
#include <stdio.h>
#include <map>
using namespace std;
const int mod = 1e9+7;
int N, M;
map<int, int> par, cnt;
int F(int x) {
	if (!par.count(x)) par[x] = x;
	if (par[x] == x) return x;
	return (par[x] = F(par[x]));
}
int mul(int x, int y) { return (long long)x * y % mod; }
int fm(int x, int y) {
	if (y == 0) return 1;
	int r = fm(x, y / 2);
	r = mul(r, r);
	if (y % 2 == 1) r = mul(r, x);
	return r;
}
int main() {
	scanf("%d%d", &N, &M);
	bool ok = 1;
	for (int i = 1; i <= M; i++) {
		int x, y; scanf("%d%d", &x, &y);
		int px = F(x), py = F(y);
		if (px == py) ok = 0;
		else par[px] = py;
	}
	int res = 0;
	if (ok) {
		for (auto x : par) cnt[F(x.first)]++;
		res = fm(N, N - par.size() + cnt.size() - 2);
		if (res < 1) res = 1;
		for (auto x : cnt) res = mul(res, x.second);
	}
	printf("%d", res);
}

Subtask #1
0.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 1212 KB Output is correct
2 Correct 0 ms 1212 KB Output is correct
3 Correct 0 ms 1212 KB Output is correct
4 Correct 0 ms 1212 KB Output is correct
5 Correct 0 ms 1212 KB Output is correct
6 Correct 0 ms 1212 KB Output is correct
7 Correct 0 ms 1212 KB Output is correct
8 Correct 0 ms 1212 KB Output is correct
9 Incorrect 0 ms 1212 KB Output isn't correct
10 Halted 0 ms 0 KB -

Subtask #2
0.0 / 91.0

# 결과 실행 시간 메모리 Grader output
1 Halted 0 ms 0 KB -