Educational Codeforces Round 52 (Rated for Div. 2) B. Vasya and Isolated Vertices

题解

题目大意 给你n个点使用m条边组成一个图 问你最多和最小能有多少个孤立节点(度为0)

最少的点个数就是每个边连两个点m-n2和0取max
最多的点计算d(d-1)=m*2用n-d 需要特判0

AC代码

#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const int INF = 0x3f3f3f3f;

int main()
{
#ifdef LOCAL
	//freopen("C:/input.txt", "r", stdin);
#endif
	ll n, m;
	cin >> n >> m;
	ll d;
	for (d = 0; d * (d + 1) <= m * 2; d++);
	cout << max(0LL, n - m * 2) << " " << n - d - 1 + (d * (d - 1) == m * 2) + (m == 0) << endl;
	 
	return 0;
}