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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)


import java.util.Arrays;
import java.util.Scanner;

public class Main {

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

	    int N=gi();
	    int[] KV=new int[100001];
	    int[] GV=new int[100001];
	    int[] V= new int[N];

        for(int i=0; i<N;i++) {
        	int a=gi();
        	V[i]=a;
        	if((i+1)%2==1) {
        		KV[a]++;
        	} else {
        		GV[a]++;
        	}
        }
	    
        Arrays.parallelSort(KV);
        Arrays.parallelSort(GV);
        long ans=0;
        if (KV[100000]==GV[100000]) {
        	if(KV[99999]>GV[99999]) {
        		if(KV[99999]== 0 && GV[99999]==0 && V[0]!=V[1]) {
        			ans=0;
        		} else if (N%2==0) {
            		ans=(N/2-KV[99999]) + (N/2-GV[100000]);
            	} else {
            	    ans=((N+1)/2-KV[99999]) + ((N-1)/2-GV[100000]);
            	}
        	} else {
        		if(KV[99999]== 0 && GV[99999]==0 && V[0]!=V[1]) {
        			ans=0;
        		} else if (N%2==0) {
            		ans=(N/2-KV[100000]) + (N/2-GV[99999]);
            	} else {
            	    ans=((N+1)/2-KV[100000]) + ((N-1)/2-GV[99999]);
            	}
        	}
        } else {
        	if(KV[99999]== 0 && GV[99999]==0 && V[0]!=V[1]) {
    			ans=0;
    		} else if (N%2==0) {
        		ans=(N/2-KV[100000]) + (N/2-GV[100000]);
        	} else {
        	    ans=((N+1)/2-KV[100000]) + ((N-1)/2-GV[100000]);
        	}
        }
	    System.out.print(ans);
	}

	// 文字列として入力を取得
	public static String gs() {
		return scanner.next();
	}

	// intとして入力を取得
	public static int gi() {
		return Integer.parseInt(scanner.next());
	}

	// longとして入力を取得
	public static long gl() {
		return Long.parseLong(scanner.next());
	}

	// doubleとして入力を取得
	public static double gd() {
		return Double.parseDouble(scanner.next());
	}
}