#include<stdio.h>
#include<math.h>
#include<stdlib.h>
int npr();
int ncr();
int fact(int num3);
int main() {
    	int choice;
    	printf("*********Menu*********\n");
    	printf("1.nPr\n2.nCr\n\n");
    	printf("Please, Enter Your Choice : ");
    	scanf("%d",&choice);
    	if(choice==1)
    	npr();
    	if(choice==2)
    	ncr();
    	return 0;
}
    	int npr()
    	{
        	int num1,num2,i,nr,answer_1,answer_2,answer_3;
        	printf("\nP(n,r) \n");
        	printf("Enter n(objects) :" );
        	scanf("%d",&num1);
        	printf("\nEnter r(sample) : ");
        	scanf("%d",&num2);
        	answer_1=fact(num1);
        	nr=num1-num2;
        	answer_2=fact(nr);
        	answer_3=answer_1/answer_2;
        	printf("\n P(n,r) : %d",answer_3);
    	}
    	int ncr()
    	{
  	int num1,num2,i,nr,answer_1,answer_2,answer_3,answer_4,answer_5;
        	printf("\nC(n,r) \n");
        	printf("Enter n(objects) :" );
        	scanf("%d",&num1);
        	printf("\nEnter r(sample) : ");
        	scanf("%d",&num2);
        	answer_1=fact(num1);
        	nr=num1-num2;
        	answer_2=fact(nr);
        	answer_3=fact(num2);
        	answer_4=answer_2*answer_3;
        	answer_5=answer_1/answer_4;
        	printf("\n C(n,r) : %d",answer_5);
    	}
    	int fact(int num3)
    	{
        	int i,ans=1;
        	for(i=1;i<=num3;i++)
        	{
            	ans=ans*i;
        	}
        	return ans;
        	}