fork download
copy 
  1. #include <stddef.h>
  2. #include <stdio.h>
  3. #include <regex.h>  
  4. #include <stdlib.h>  
  5. #include <string.h>    
  6.  
  7. int main (int argc, char *argv[])
  8. {
  9. 	/*
  10.     if (argc < 2) {
  11.         fprintf(stderr, "Usage: %s number\n", argv[0]);
  12.         return(1);
  13.     }
  14.  
  15.     int num = atoi(argv[1]);
  16.     */
  17.     int num=41;
  18.     printf("%d\n",num);
  19.  
  20.     regex_t regex;
  21.     char    buf [255];
  22.     char    str [num+1];
  23.  
  24.     memset(str,'1',num);
  25.     str[num] = 0;
  26.     puts(str);
  27.  
  28.     regcomp(&regex, "^(11+)\\1+$", REG_EXTENDED);
  29.  
  30.     int r = regexec(&regex, str, 0, NULL, 0);
  31.  
  32.     //If a match is found, the regexec() function returns 0. 
  33.     if (0 == r) {
  34.         puts("Not Prime");
  35.     }
  36.     //If no match is found, the regexec() function returns REG_NOMATCH. 	
  37.     else if (REG_NOMATCH == r) {
  38.         puts("Prime");
  39.     }
  40.     //Otherwise, it returns a nonzero value indicating an error. 		
  41.     else {
  42.         regerror(r, &regex, buf, sizeof(buf));
  43.         fprintf(stderr, "Error: %d %s\n",r , buf);
  44.         return(1);
  45.     }
  46.  
  47. }
  48.  
Success #stdin #stdout 4.31s 4508KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
41
11111111111111111111111111111111111111111
Prime
https://ideone.com/2MelzP
language:
C (gcc 8.3)
created:
3 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!