C program to calculate nPr value?

Permutation and combination, nPr can also be expressed as P(n,r), which is a mathematical formula used to calculate the number of permutations. The formula of P(n,r) is n! / (n – r)!.

The number of permutations on a set of n elements is given by n!, where "!" represents factorial. The Chinese translation of

Input:n=5;r=4;
Output:120

Explanation

is:

Explanation

P(5, 4) = 5! / (5-4)! => 120 / 1 = 120
5!=1*2*3*4*5*=120

Example

The Chinese translation is:

Example

#include<iostream>
using namespace std;
long int fact(int x) {
   int i, f=1;
   for(i=2; i<=x; i++) {
      f=f*i;
   }
   return f;
}
int main() {
   int n, r;
   long int npr;
   n=5;
   r=4;
   npr=fact(n)/fact(n-r);
   printf("%d",npr);
}

The above is the detailed content of C program to calculate nPr value?. For more information, please follow other related articles on the PHP Chinese website!