[AtCoder ARC103A]////

Posted 2021-01-11 memory-of-winter

题目大意：给你一串长度为$n$的序列，要求把这个序列变成$ababdots abab$的形式，且$a ot =b$，问最少要改几个数字

题解：求出奇偶位上前二多的数字就判断一下就行了

卡点：无

 

C++ Code：

#include <cstdio>
#define maxn 100010
int cnt[2][maxn], M[2], Q[2], m[2], q[2];
int n;
int main() {
	scanf("%d", &n); 
	for (int i = 1, x, p; i <= n; i++) {
		scanf("%d", &x); p = i % 2;
		cnt[p][x]++;
		if (M[p] < cnt[p][x]) M[p] = cnt[p][x], Q[p] = x;
	}
	if (Q[0] != Q[1]) {
		printf("%d
", n - M[0] - M[1]);
		return 0;
	}
	for (int i = 1; i <= 100000; i++) {
		if (m[0] < cnt[0][i] && i != Q[0]) m[0] = cnt[0][i], q[0] = i;
		if (m[1] < cnt[1][i] && i != Q[1]) m[1] = cnt[1][i], q[1] = i;
	}
	if (M[0] - m[0] > M[1] - m[1]) printf("%d
", n - M[0] - m[1]);
	else printf("%d
", n - m[0] - M[1]);
	return 0;
}