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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;

public class Main {
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int v[] = new int[n];
		for(int i = 0; i < n; i++) {
			v[i] = sc.nextInt();
		}
		
		int odd[] = new int[n / 2];
		int even[] = new int[n / 2];
		
		for(int i = 0; i < n; i++) {
			if(i % 2 == 1) {
				odd[i / 2] = v[i];
			} else {
				even[i / 2] = v[i];
			}
		}
		Arrays.sort(odd);
		Arrays.sort(even);
		
		int ans_even = 0;
		int ans_odd = 0;
		int temp_even = 0;
		int temp_odd = 0;
		int temp_even_num = 0;
		int temp_odd_num = 0;
		int odd_next = 0;
		int even_next = 0;
		for(int i = 0; i < n / 2; i++) {
			if(temp_even_num != even[i]) {
				//ans_even = Math.max(ans_even, temp_even);
				if(temp_even > ans_even) {
					even_next = ans_even;
					ans_even = temp_even;
				}
				temp_even = 1;
				temp_even_num = even[i];
			} else {
				temp_even++;
			}
			
			if(temp_odd_num != odd[i]) {
				if(temp_odd > ans_odd) {
					odd_next = ans_odd;
					ans_odd = temp_odd;
				}
				//ans_odd = Math.max(ans_odd, temp_odd);
				temp_odd = 1;
				temp_odd_num = odd[i];
			} else {
				temp_odd++;
			}
		}
		ans_even = Math.max(ans_even, temp_even);
		ans_odd = Math.max(ans_odd, temp_odd);
		if(ans_even != ans_odd) {
			System.out.println(n - ans_even - ans_odd);
		} else {
			if(odd_next > even_next) {
				System.out.println(n - ans_even - odd_next);
			} else {
				System.out.println(n - even_next - ans_odd);
			}
		}
	}
}