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  1. #include <stdio.h>
  2. #include <ctype.h>
  3.  
  4. int isInt(const char *str);
  5.  
  6. int main()
  7. {
  8. 	printf("%d\n", isInt("1+"));
  9. 	printf("%d\n", isInt("+"));
  10. 	printf("%d\n", isInt("asf"));
  11. 	printf("%d\n", isInt("1a"));
  12. 	printf("%d\n", isInt("1a1"));
  13. 	printf("%d\n", isInt("+1"));
  14. 	printf("%d\n", isInt("-1"));
  15. 	printf("%d\n", isInt("1"));
  16.  
  17. 	return 0;
  18. }
  19.  
  20. int isInt(const char *str)
  21. {
  22. 	int i = 0;
  23.  
  24. 	if (str[0] == '\0')
  25. 		return 0;
  26.  
  27. 	if ((str[0] == '+' || str[0] == '-') && str[1] != '\0')
  28. 		i++;
  29.  
  30. 	while (str[i] != '\0')
  31. 	{
  32. 		if (!isdigit(str[i]))
  33. 			return 0;
  34.  
  35. 		i++;
  36. 	}
  37.  
  38. 	return 1;
  39. }
Success #stdin #stdout 0s 4408KB
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https://ideone.com/vnoZTW
language:
C (gcc 8.3)
created:
4 years ago
visibility:
public

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