float fakt (int n) 
  { 
        float f; int i; 
        f=1; 
        for(i=1;i<=n;i++) 
        f=f*i; 
        return f; 
  } 
  

 
  #include <stdio.h> 
   
  void permutit (int *nPtr, int *rPtr) 
  { 
       int Q; float f1; float f2; int i; 
             
       for(i=1;i<=*nPtr;i++) 
       { 
                        f1=f1*i; 
       } 
        
       for(i=1;i<=(*nPtr-*rPtr);i++) 
       { 
                        f2=f2*i; 
       } 
        
       Q=f1/f2; 
        
       printf("Permutation of %d with %d is %f...\n",*nPtr,*rPtr,Q); 
        
  } 
   
  int main() 
  { 
      int a,b; 
      int P; 
       
      printf("give the x and y integers in P(x,y) in order: "); 
      scanf("%d %d",a,b); 
      permutit(a,b); 
       
      system ("pause"); 
      return 0; 
  }