/* check id_card  * write by sndnvaps<sndnvaps@gmail.com>* ai -> a1 , a2, a3, a4, a5, a6... a17 (a18 是校验码) 身份证前17位对应(ai)* wi -> 7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2 (17位)*  *  int  res = 0;*  for (i = 1; i < 17; i++) {*          res += (a[i] * w[i])*          }*     int  y = res % 11；* ** y 与 a18的对应关系**  y    { 0, 1,  2,  3, 4, 5, 6, 7, 8, 9, 10}*  a18  { 1, 0, 'X', 9, 8, 7, 6, 5, 4, 3,  2 } -> vefiry[18] = { 1, 0, 'X', 9, 8, 7, 6, 5, 4, ,3, 2};*/#include <stdio.h>
#include <stdlib.h>
#include <string.h>int wi[17] = { 7, 9, 10, 5, 8 , 4, 2, 1, 6, 3, 7, 9 , 10, 5, 8, 4, 2};
int a18[11] = { 1, 0, 'X', 9, 8, 7, 6, 5, 4, 3, 2};int char2int(char n) {return (n - 48);
}int check_id(char id[17] ) {//return yint res = 0;int y;int i;for (i = 0; i < 17; i++) {res += (char2int(id[i]) * wi[i]);}y = res % 11;return y;
}int verify_id_t(int verify_id, int id_v) { //verify_id = y; id_v = a18int i;int temp; //store the i ; for (i = 0; i < 10; i++) {if (i == verify_id) {temp = a18[i];printf("a18[%d] = %d\n", i, temp);break;}}if (temp == id_v)return 1; // get it , 验证合格return 0;
}void usage() {printf("check_id_card id_card_num \n");
}int main(int argc, char *argv[]) {if (argc < 2) {usage();}char id_string[18];int id_18;int i;int y;if (strlen(argv[1]) > 18) {printf("id_card_num must be 18 bits\n");        return 0;}strncpy(id_string, argv[1], 18);id_18 = char2int(id_string[17]);id_string[17] = '\0';printf("id_18 = %d\n", id_18);y = check_id(id_string);if(verify_id_t(y, id_18) == 1) {printf("verify success\n");} else {printf("verify failed\n");}return 0;
}