Codeforces Round #521 (Div. 3) D. Cutting Out

题解

题目大意 给你一个序列 让你找到一个长度为k的序列 在原序列当中出现的次数最多

满足单调性 二分出现次数 然后根据出现次数随意输出一个序列

AC代码

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

const int INF = 0x3f3f3f3f;
const int MAXN = 2e5 + 10;
int a[MAXN];
int N, K;

bool check(int m)
{
	int cnt = K;
	for (int i = 1; i < MAXN; i++)
		cnt -= a[i] / m;
	if (cnt <= 0)
		return true;
	return false;
}
int main()
{
#ifdef LOCAL
	freopen("C:/input.txt", "r", stdin);
#endif
	int x;
	cin >> N >> K;
	for (int i = 1; i <= N; i++)
		scanf("%d", &x), a[x]++;
	int l = 1, r = N, ans = 1; //切次数
	while (l <= r)
	{
		int m = l + r >> 1;
		if (check(m))
			l = m + 1, ans = m;
		else
			r = m - 1;
	}
	int fst = 1;
	for (int i = 1; i < MAXN; i++)
	{
		for (int j = 0; j < a[i] / ans; j++)
		{
			fst ? fst = 0 : putchar(' ');
			printf("%d", i);
			K--;
			if (K <= 0)
				cout << endl, exit(0);
		}
	}

	return 0;
}