完数：一个数恰好等于它的所有因子之和，eg：6=1+2+3
public class wanshu {
public static void main(String
[] args
) {
for (int i
= 1 ; i
<= 1000 ; i
++) {
int factor
= 0 ;
for (int j
= 1 ; j
<= i
/2 ; j
++) {
if (i
% j
== 0) {
factor
+= j
;
}
} if (factor
== i
) {
System
.out
.println(i
);
}
}
}
}
