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.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] a = new int[n / 2];
        int[] b = new int[n / 2]; 
        for (int i = 0; i < n /2; i++) {
            a[i] = sc.nextInt();
            b[i] = sc.nextInt();
        }
        Arrays.sort(a);
        Arrays.sort(b);
        int aMaxcount = 1;
        int aSecondCount = 1;
        int amaxnum = 0;
        int amaxNum2 = 0;
        int acount = 1;
        for (int i = 0; i < n / 2 - 1; i++) {
            if (a[i] == a[i + 1]) {
                acount++;
                if (acount > aMaxcount) {
                    aMaxcount = acount;
                    amaxnum = i;
                }

            } else {
                acount = 1;
            }
        }
        for (int i = 0; i < n / 2 - 1; i++) {
            if (a[i] == a[amaxnum]) {
                acount = 1;
                break;
            }
            if (a[i] == a[i + 1]) {
                acount++;
                if (acount > aSecondCount) {
                    aSecondCount = acount;
                    amaxnum = i;
                }

            } else {
                acount = 1;
            }

        }

        int bMaxcount = 1;
        int bSecondCount = 1;
        int bmaxnum = 0;
        int bmaxNum2 = 0;
        int bcount = 1;
        for (int i = 0; i < n / 2 - 1; i++) {
            if (b[i] == b[i + 1]) {
                bcount++;
                if (bcount > bMaxcount) {
                    bMaxcount = bcount;
                    bmaxnum = i;
                }

            } else {
                bcount = 1;
            }
        }
        for (int i = 0; i < n / 2 - 1; i++) {
            if (b[i] == b[amaxnum]) {
                bcount = 1;
                break;
            }
            if (a[i] == a[i + 1]) {
                bcount++;
                if (bcount > bSecondCount) {
                    bSecondCount = bcount;
                    bmaxnum = i;
                }

            } else {
                bcount = 1;
            }

        }
        int ans = 0;
        int aaa = 0;
        int bbb = 0;
        if (a[amaxnum] != b[bmaxnum]) {
            ans = n - aMaxcount - bMaxcount;
        } else if(aMaxcount == n / 2){
            ans = n / 2;
        }else{
            aaa = n - aMaxcount - bSecondCount;
            bbb = n - aSecondCount - bMaxcount;
            ans = Math.max(aaa, bbb);
        }
        System.out.println(ans);
        
    }
}