完數的實現

public class PerfectNumber {

	public static void main(String[] args) {
    
		int i, j, sum;      /* i表示要判斷的數，j表示因子，sum表示因子之和*/ 
		for (i = 2; i <= 1000; i++){
			sum = 1;
			
			for (j = 2; j <= i / 2; j++)
				if (i%j == 0)         
					sum += j;

			if (sum == i){
				System.out.print("完數"+i+"因子爲1 ");   

				for (j = 2; j <= i/2; j++)
					if (i%j == 0)
						System.out.print(" "+j);    
				System.out.println();
			}
		}
	}
}