1. bool checkID(string strIDNum) {
    2.     int weight[] = {7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2};
    3.     char validate[] = {'1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'};
    4.     int sum = 0;
    5.     int mode = 0;
    6.     int i = 0;
    7.     int length = strIDNum.length();
    8.     if (length == 18) {
    9.         for (
    10.                 i = 0;
    11.                 i < length - 1; i++) {
    12.             sum = sum + (strIDNum[i] - '0') * weight[i];
    13.         }
    14.         mode = sum % 11;
    15.         if (validate[mode] == strIDNum[17]) {
    16.             return true;
    17.         }
    18.     }
    19.     return false;
    20. }