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  1. #include <stdio.h>
  2. 	#include <stdbool.h>
  3. 	#include <string.h>
  4.  
  5. 	const char* units[] = {"I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX", "X"};
  6. 	const char* tens[] = {"X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC", "C"};
  7. 	const char* hundreds[] = {"C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM", "M"};
  8. 	const char* symbols = "IVXLCDM";
  9.  
  10. 	void to_roman(int number, char *result);
  11. 	bool has_one(const char *haystack, char needle);
  12. 	int main(void)
  13. 	{
  14. 		for(int number = 1; number < 2000; number++)
  15. 		{
  16. 			bool ok = true;
  17. 			char roman[100];
  18. 			to_roman(number, roman);
  19. 			for(int s = 0; symbols[s]; s++)
  20. 			{
  21. 				if(!has_one(roman, symbols[s]))
  22. 				{
  23. 					ok = false;
  24. 					break;
  25. 				}
  26. 			}
  27. 			if(ok)
  28. 				printf("%d : %s\n", number, roman);
  29. 		}
  30. 		return 0;
  31. 	}
  32.  
  33. 	bool has_one(const char *haystack, char needle)
  34. 	{
  35. 		int count = 0;
  36. 		for(int i = 0; haystack[i]; i++)
  37. 			if(haystack[i] == needle && ++count == 2)
  38. 				return false;
  39. 		return count == 1;
  40. 	}
  41.  
  42. 	void to_roman(int number, char *result)
  43. 	{
  44. 		int M = (number / 1000) % 10;
  45. 		int C = (number / 100) % 10;
  46. 		int X = (number / 10) % 10;
  47. 		int I = (number / 1) % 10;
  48. 		result[0] = '\0';
  49. 		if(M != 0)
  50. 			strcat(result, "M");
  51. 		if(C != 0)
  52. 			strcat(result, hundreds[C - 1]);
  53. 		if(X != 0)
  54. 			strcat(result, tens[X - 1]);
  55. 		if(I != 0)
  56. 			strcat(result, units[I - 1]);
  57. 	}
Success #stdin #stdout 0s 10320KB
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stdin
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Standard input is empty
stdout
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1444 : MCDXLIV
1446 : MCDXLVI
1464 : MCDLXIV
1466 : MCDLXVI
1644 : MDCXLIV
1646 : MDCXLVI
1664 : MDCLXIV
1666 : MDCLXVI
https://ideone.com/o6FJG0
language:
C (gcc 8.3)
created:
8 years ago
visibility:
public

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