Problem:
Score : 300 points

Problem Statement

A sequence a_1,a_2,... ,a_n is said to be /\/\/\/ when the following conditions are satisfied:

For each i = 1,2,..., n-2, a_i = a_{i+2}.

Exactly two different numbers appear in the sequence.

You are given a sequence v_1,v_2,...,v_n whose length is even.
We would like to make this sequence /\/\/\/ by replacing some of its elements.
Find the minimum number of elements that needs to be replaced.

Constraints

2 \leq n \leq 10^5

n is even.

1 \leq v_i \leq 10^5

v_i is an integer.

Input

Input is given from Standard Input in the following format:

n
v_1 v_2 ... v_n

Output

Print the minimum number of elements that needs to be replaced.

Sample Input 1

4
3 1 3 2

Sample Output 1

1

The sequence 3,1,3,2 is not /\/\/\/, but we can make it /\/\/\/ by replacing one of its elements: for example, replace the fourth element to make it 3,1,3,1.

Sample Input 2

6
105 119 105 119 105 119

Sample Output 2

0

The sequence 105,119,105,119,105,119 is /\/\/\/.

Sample Input 3

4
1 1 1 1

Sample Output 3

2

The elements of the sequence 1,1,1,1 are all the same, so it is not /\/\/\/.

Solution in C (GCC 5.4.1) (judge verdict: Accepted)

#include<stdio.h>
int main() {
	int n, m, a, b, s[200005] = {}, t[200000][2] = {}, max = 0, max2 = 0, smax = 0, smax2 = 0, memo = 0,memo2=0;
	scanf("%d", &n);

	for (int i = 1; i <= n; i++) {
		scanf("%d", &s[i]);
		if (i % 2 == 1) {
			t[s[i]][0]++;
		}
		else {
			t[s[i]][1]++;
		}
	}
	for (int i = 1; i <= 100000; i++) {
		if (t[i][0] >= max) {
			
			max = t[i][0];
			memo = i;
		}
		
		if (t[i][1] >= max2) {
			
			max2 = t[i][1];
			memo2 = i;
			
		}
	}
	t[memo][0] = 0;
	t[memo2][1] = 0;
	for (int i = 1; i <= 100000; i++) {
		if (t[i][0] >= smax) {
			
			smax = t[i][0];
			
		}

		if (t[i][1] >= smax2) {
			
			smax2 = t[i][1];
			

		}
	}
	if (memo != memo2) {
		printf("%d", n - max - max2);
	}
	else {
		if (smax >= smax2) {
			printf("%d", n - smax - max2);
		}
		else {
			printf("%d", n - max - smax2);
		}
	}
}