fork download 
  1. #include <stdio.h>
  2. #include <ctype.h>
  3. #define  is_delim(c)  (isspace((c)) || ispunct((c)))
  4. #define  N_EVEN  1
  5. #define  N_ODD   2
  6.  
  7.  
  8. int is_altern(const char* s){
  9. 	const char* p;
  10. 	int j, n = 0, i = 0, r = (*s != '\0');
  11.  
  12. 	for(; *s; s = p){
  13. 		while(is_delim(*s))
  14. 			++s;
  15.  
  16. 		for(p = s; *p && !is_delim(*p); ++p)
  17. 			;
  18.  
  19. 		if((j = (int)(p - s)) > 0){
  20. 			if(j & 1)
  21. 				i = N_ODD;
  22. 			else
  23. 				i = N_EVEN;
  24.  
  25. 			if(i != n)
  26. 				n = i;
  27. 			else {
  28. 				r = 0;
  29. 				break;
  30. 			}
  31. 		}
  32. 	}
  33. 	return r;
  34. }
  35.  
  36.  
  37. int main(void){
  38. 	puts( is_altern("lisp, apl, pascal.") ? "yes" : "no");
  39. 	puts( is_altern("titan moon (venus)") ? "yes" : "no");	
  40. 	puts( is_altern("Forth Java Prolog")  ? "yes" : "no");
  41. 	return 0;
  42. }
  43.  
Success #stdin #stdout 0s 2156KB
comments (?)
stdin 
Standard input is empty
stdout 
yes
yes
no
https://ideone.com/pIy038
language:
C (gcc 8.3)
created:
9 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!