fork(1) download 
  1. #include<stdio.h>
  2. #include<string.h>
  3. #define MOD 1000000007
  4. long long fact(long long x)
  5. {
  6. 	long long f=1;
  7. 	if(x==0)
  8. 		return 1;
  9. 	else
  10. 	{
  11. 		for(int i=1;i<=x;i++)
  12. 			f=f*(i%MOD);
  13. 	}
  14. 	return f%MOD;
  15. }
  16. long long square(long long x)
  17. {
  18. 	return x*x;
  19. }
  20. long long power(long long base,long long expo)
  21. {
  22. 	if(base==0)
  23. 		return 0;
  24. 	if(expo==0)
  25. 		return 1;
  26. 	else
  27. 	{
  28. 		if(expo%2==0)
  29. 			return square(power(base,expo/2))%MOD;
  30. 		else
  31. 			return (base*power(base,expo-1))%MOD;
  32. 	}
  33. }
  34. int main()
  35. {
  36. 	int arr[26];
  37. 	char ip[1000000];
  38. 	scanf("%s",ip);
  39. 	long long num,den=1;
  40. 	int len=strlen(ip);
  41. 	for(int i=0;i<len;i++)
  42. 		arr[ip[i]-'a']++;
  43. 	for(int i=0;i<26;i++)
  44. 		arr[i]/=2;
  45. 	num=fact(len/2);
  46. 	for(int i=0;i<26;i++)
  47. 	{
  48. 		den=den*(fact(arr[i]));
  49. 	}
  50. 	den=den%MOD;
  51. 	den=power(den,MOD-2);
  52. 	printf("%lld\n",((num%MOD)*(den%MOD))%MOD);
  53. 	//printf("%lld",fact((long long)5));
  54. }
Success #stdin #stdout 2.59s 3148KB
comments ()
stdin 
Standard input is empty
stdout 
0
https://ideone.com/PnStBF
language:
C99 (gcc 8.3)
created:
10 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!