P5.java

import java.util.*;
import java.io.*;

public class P5 {
    public static void sort012(int[] arr) {
        int n = arr.length;
        int low = 0;
        int high = n - 1;
        int mid = 0;
        while (mid <= high) {
            if (arr[mid] == 0) {
                int temp = arr[mid];
                arr[mid] = arr[low];
                arr[low] = temp;
                low++;
                mid++;
            } else if (arr[mid] == 2) {
                int temp = arr[mid];
                arr[mid] = arr[high];
                arr[high] = temp;
                high--;
            } else
                mid++;
        }
    }
}