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) {

		int n;
		int[] v;
		int ans = 0;

		try (Scanner sc = new Scanner(System.in)) {
			n = sc.nextInt();
			if (n % 2 == 1 || n < 2 || n > 100000) {
				System.out.println("n を制約通り入力してください");
				return;
			}

			v = new int[n];

			for (int i = 0; i < n; i++) {
				v[i] = sc.nextInt();
				if (v[i] < 1 || v[i] > 100000) {
					System.out.println("v を制約通り入力してください");
					return;
				}
			}
			Arrays.sort(v);

			if (v[0] == v[v.length - 1]) {
				System.out.println(v.length / 2);
				return;
			}

			int containsCountMin = 0;
			int containsCountMax = 0;
			for (int i = 0; i < v.length; i++) {
				if (v[0] == v[i])
					containsCountMin++;
				if (v[v.length - 1] == v[i])
					containsCountMax++;
			}

			if (containsCountMin > v.length / 2)
				containsCountMin = v.length / 2;

			if (containsCountMax > v.length / 2)
				containsCountMax = v.length / 2;

			ans = Math.abs(containsCountMin - v.length / 2) + Math.abs(containsCountMax - v.length / 2);
			System.out.println(ans);

		} catch (Exception e) {
			System.out.println(e);

		} finally {

		}

	}

}