Increase Sequence

Increase Sequence

时间限制：1000 ms  |  内存限制：65535 KB

难度：2

描述

You have an array A with N elements.

Your goal is to change it into an array  that contains each number from 1 to N exactly once. The change will consist of zero or more steps. In each step, you may pick an arbitrary element of A and increase its value by k. You may pick the same element multiple times. Note that you are not allowed to decrease the value of any element.

输入

There are multiple cases.
For each input case, the first line contains two integers N and k ,the second line contains N intergers A[i]
(i=0,1,2,…，N-1).
(1≤N,A[i]≤50,1≤k≤10)

输出

Print “POSSIBLE”if you can achieve your goal, print “IMPOSSIBLE” otherwise.

样例输入

5 2
1 2 3 3 5
4 3
1 4 3 2

样例输出

IMPOSSIBLE
POSSIBLE

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

public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		while (scanner.hasNext()) {
			int number = scanner.nextInt();
			int value = scanner.nextInt();
			int arr[] = new int[number];
			boolean flag = true;
			for (int i = 0; i < number; i++) {
				arr[i] = scanner.nextInt() - 1;
			}
			Arrays.sort(arr);
			for (int i = 0; i < number;) {
				if (arr[i] == i) {
					i++;
					continue;
				}
				while (arr[i] < i) {
					arr[i] += value;
				}
				Arrays.sort(arr);
				if (arr[i] > i) {
					flag = false;
					break;
				}
			}
			if (flag) {
				System.out.println("POSSIBLE");
			} else {
				System.out.println("IMPOSSIBLE");
			}
		}
	}
}