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: Accepted)

import java.util.Scanner;

class Main {
  public static int min(int a, int b) {
    return a < b ? a : b;
  }

  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    int n = scanner.nextInt();
    int[][] counts = new int[2][100001];
    for (int i = 0; i < n; i++) {
      counts[i % 2][scanner.nextInt()]++;
    }
    int[][] maxCnt = { { 0, 0 }, { 0, 0 } };
    int[] maxValue = { 0, 0 };
    for (int i = 0; i <= 100000; i++) {
      for (int j = 0; j < 2; j++) {
        if (counts[j][i] > maxCnt[j][0]) {
          maxCnt[j][1] = maxCnt[j][0];
          maxCnt[j][0] = counts[j][i];
          maxValue[j] = i;
        } else if (counts[j][i] > maxCnt[j][1]) {
          maxCnt[j][1] = counts[j][i];
        }
      }
    }
    int[] e1 = { maxCnt[0][0], maxValue[0] }, o1 = { maxCnt[1][0], maxValue[1] };
    int e2 = maxCnt[0][1], o2 = maxCnt[1][1];
    if (e1[1] != o1[1]) {
      System.out.println(n - e1[0] - o1[0]);
    } else {
      System.out.println(min(n - e1[0] - o2, n - e2 - o1[0]));
    }
  }
}