NCR

Problem Statement


In this program we will code a basic program to calculate NCR & NPR in C Programming language.

Code

#include

int fact(int num)

{

int f=1;

int i;

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

{

  f=f*i;  

}

return f;

}

int main()

{

int n,r;

int ncr,npr;

printf("nCr & nPr CALCULATOR :\n");

printf("ENTER THE VALUES OF n & r :\n");

scanf("%d %d",&n,&r);

ncr=fact(n)/(fact(r)*fact(n-r));

npr=fact(n)/(fact(n-r));

printf("%dC%d : %d\n",n,r,ncr);

printf("%dP%d : %d",n,r,npr);

return 0;

}

Output

nCr & nPr CALCULATOR :

ENTER THE VALUES OF n & r : 5 0

5C0 : 1

5P0 : 1 

Explanation 

In this problem we have to generate the measure of nCr and nPr for given values of 'n' and 'r'. We have following formulas to calculate nCr and nPr respectively :

ⁿC_r = n! / r!*(n-r)!

ⁿP_r = n! /(n-r)!

Now after breaking this formula,we see that,all we have to do is find the factorial of each parameter i.e n,r,n-r. So,after finding the factorial,we put the values in formula.