身份证号码判别

int check(char* str);
int main(){
	FILE *fp;
	char file_idnum[20];
	if(!(fp=fopen("data.txt","r"))){
		printf("cant open the doc!\n");
		exit(0);
	}
	while(!feof(fp)){
		fgets(file_idnum,20,fp);
		//printf("***%s*****",file_idnum);
		if(file_idnum[0]=='\n'){
			continue;
		}
		if(!check(file_idnum)){
			printf("不合法的身份证号是：%s",file_idnum);
		}
	}
	fclose(fp);
}
int check(char* str){
	int i,j;
	int weight[] = {7,9,10,5,8,4,2,1,6,3,7,9,10,5,8,4,2};
	char M[11]={'1','0','X','9','8','7','6','5','4','3','2'};
	int sum =0;
	char last;
	int temp[18];
	for(j=0;j<17;j++){
		 temp[j] = str[j] - '0';
	}
	last = str[j];
	for(i=0;i<17;i++){
		int k =temp[i];
		int m = weight[i];
		sum =sum+k*m;
	}

	if(M[sum%11] == last){
		return 1;
	}else{
		return 0;
	}

}
`