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.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);

        try{
            //入力
            int n = scan.nextInt();
            int[] v = new int[n];
            for(int i = 0; i < n; i++){
                v[i] = scan.nextInt();
            }

            int[][] ans = new int[2][100001];
            for(int i = 0; i < n; i++){
                if(i % 2 == 0){
                    ans[0][v[i]]++;
                }else{
                    ans[1][v[i]]++;
                }
            }


            int num = 0;

            int even = calcNum(ans[0]);
            int odd = calcNum(ans[1]);
            int evenNum = ans[0][even];
            int oddNum = ans[1][odd];
            if(even == odd){
                ans[0][even] = 0;
                ans[1][odd] = 0;
                int even2 = calcNum(ans[0]);
                int odd2 = calcNum(ans[1]);
                int even2Num = ans[0][even2];
                int odd2Num = ans[0][odd2];
                if(evenNum + odd2Num >= oddNum + even2Num){
                    num = n-evenNum-odd2Num;
                }else{
                    num = n-oddNum-even2Num;
                }
            }else{
                num = n-evenNum-oddNum;
            }

            System.out.println(num);

        }finally{
            scan.close();
        }
    }

    static int calcNum(int[] ansEven){
        int max = -1;
        for(int i = 0; i < 100000; i++){
            if(max < ansEven[i]){
                max = i;
            }
        }
        return max;
    }

}