[推荐] 求21亿一下自守数 [问题点数：0分]

[悔棋先生]

public class SelfDefenseNumber {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
for(long i = 0L; i < 2147483648l; ++i) {
long j = i * i;
String a = Long.toString(i);
String c = Long.toString(j);
if(isEndWith(c.toCharArray(),a.toCharArray())) {
System.out.println(String.format("%s X %s = %s", a, a, c));
}
}
}

private static boolean isEndWith(char[] main, char[] sub) {
final int length = sub.length + 1;
for(int i = 1; i < length; ++i) {
if(main[main.length - i] == sub[sub.length - i]) {
continue;
}
return false;
}
return true;
}

}

[悔棋先生]

0 X 0 = 0 1 X 1 = 1 5 X 5 = 25 6 X 6 = 36 25 X 25 = 625 76 X 76 = 5776 376 X 376 = 141376 625 X 625 = 390625 9376 X 9376 = 87909376 90625 X 90625 = 8212890625 109376 X 109376 = 11963109376 890625 X 890625 = 793212890625 2890625 X 2890625 = 8355712890625 7109376 X 7109376 = 50543227109376 12890625 X 12890625 = 166168212890625 87109376 X 87109376 = 7588043387109376 212890625 X 212890625 = 45322418212890625 787109376 X 787109376 = 619541169787109376 1787109376 X 1787109376 = 3193759921787109376 不好意思，本人的分太少了，目前好像只有30分，所以是0分贴

[悔棋先生]

不以0，1，5，6结尾的数必然不是自守数