Problem 52

问题描述：

It can be seen that the number, 125874, and its double, 251748, contain exactly the same digits, but in a different order.

Find the smallest positive integer, x, such that 2x, 3x, 4x, 5x, and 6x, contain the same digits.

解决问题：

package projecteuler;

import java.util.Arrays;

public class Problem52 {

	public static boolean IsNumber(int number){

		int tmp = number;
		boolean[] elements = new boolean[10];
		Arrays.fill(elements, false);
		
		while(tmp!=0){
			elements[tmp%10] = true;
			tmp = tmp/10;
		}
		
		for(int i=2; i<7; i++){
			int value = number*i;
			while(value!=0){
				if(!elements[value%10])
					return false;
				value = value/10;
			}
		}
		
		return true;
	}
	
	public static void main(String[] args){
		boolean found = false;
		int begin = 100;
		int last = 200;
		int ans = 0;
		do{
			int i = begin +1;
			for(;i<last; i++){
				if(IsNumber(i)){
					ans = i;
					found = true;
					break;
				}
			}
			begin *= 10;
			last *= 10;
		}while(!found);
		System.out.println("Ans:"+ans);
		System.out.println(IsNumber(142857));
	}
}