C++ Program to calculate factorial and also calculate Permutation and Combination .

PERMUTATION AND COMBINATION

C++ CODE :)

 

#include<iostream>

using namespace std;

long factorial(int A);

long find_ncr(int x, int y);

long find_npr(int t, int s);

int main()

{

int n, r;

long nCr, nPr;

cout<<"Enter n = ";

cin>>n;

cout<<"Enter r = ";

cin>>r;

nCr = find_ncr(n,r);

nPr = find_npr(n,r);

cout<<"1) Combination of "<<n<<" and "<<r<<" is = "<<nCr<<endl;

cout<<"2) Permutation of "<<n<<" and "<<r<<" is = "<<nPr<<endl;

return 0;

}

long find_ncr(int x, int y )

{

long result;

result=factorial(x)/factorial(x-y)*factorial(y);

return (result);

}

long find_npr(int t, int s)

{

long result1;

result1=factorial(t)/factorial(t-s);

return (result1);

}

long factorial(int A)

{

int i;

long r=1;

for( i=1;i<=A;i++ )

r=r*i;

return (r);

}

Input && Output :)