The factorial of a number 'n' is the product of all number from 1 upto the number 'n'it is denoted by n!. For example n=5 then factorial of 5 will be 1*2*3*4*5= 120. 5!= 120
Factorial program C++ Logic:
- First think what is the factorial of a number? How mathematically it can be calculated.
- If you got this info then it will be very easier to make a C++ Program logic to find the factorial.
- User enters a number and we have to multiply all numbers upto entered number.
- Like if user enters 6 then Factorial should be equal to factorial= 1*2*3*4*5*6.
- In this case a for Loop will be very helpful. It will start from one and multiply all numbers upto entered number after it loop will be terminated.
- Take a variable and initialized it to 1 and in loop store multiplication result into it like in below program a variable
- Factorial is used for this purpose.what is we does not initialized it to 1 and initialized it to zero or remain it uninitialized. In case of 0 our result will be zero in case of any number entered
- In case of not initializing it our answer will correct mostly but if variable contains garbage value then we will not be able to get correct result.
- It is recommended that to initialize it to one.
C++ program to find factorial of any number
#include<iostream.h>
using namespace std;
int main()
{
int num,factorial=1;
cout<<" Enter Number To Find Its Factorial: ";
cin>>num;
for(int i=1;i<=num;i++)
{
factorial=factorial*i;
}
cout<<"Factorial of Given Number is ="<<factorial<<endl;
return 0;
}
Output
Enter Number To Find Its Factorial: 6
Factorial of Given Number is = 720
