blackhole.java

关于一些算法的例子

public class BlackHole{
	public static void main(String args[]){
		int n = 1234;

		int tmp = n;
		while (tmp != 6174){
			int[] a = new int[4];
			for(int i = 0; i<4; ++i){
				a[i] = tmp % 10;
				tmp /= 10;
			}

			for (int i = 0; i< a.length; ++i)
				for(int j = 0; j<i; ++j)
					if(a[j] > a[i]){
						int tmp2 = a[j];
						a[j] = a[i];
						a[i] = tmp2;
					}

			int max, min;
			max = min = 0;
			for (int i = 0; i<a.length; ++i){
				max = max*10 + a[a.length -1 -i ];
				min = min*10 + a[i];
			}
			tmp = max - min;
			System.out.println(max +" - " + min + " = " + tmp);
		}

	}
}