Given with the number n the task is to calculate the factorial of a number. Factorial of a number is calculated by multiplying the number with its smallest or equal integer values.
Factorial is calculated as −
0! = 1 1! = 1 2! = 2X1 = 2 3! = 3X2X1 = 6 4! = 4X3X2X1= 24 5! = 5X4X3X2X1 = 120 . . . N! = n * (n-1) * (n-2) * . . . . . . . . . .*1
Example
的中文翻译为：示例
Input 1 -: n=5 Output : 120 Input 2 -: n=6 Output : 720
There are multiple methods that can be used −
- Through the loops
- Through recursion which is not at all effective
- Through a function
Given below is the implementation using functions
Algorithm
Start
Step 1 -> Declare function to calculate factorial
int factorial(int n)
IF n = 0
return 1
End
return n * factorial(n - 1)
step 2 -> In main()
Declare variable as int num = 10
Print factorial(num))
Stop使用C语言
例子
#include// function to find factorial int factorial(int n){ if (n == 0) return 1; return n * factorial(n - 1); } int main(){ int num = 10; printf("Factorial of %d is %d", num, factorial(num)); return 0; }
输出
Factorial of 10 is 3628800
使用C++
示例
#includeusing namespace std; // function to find factorial int factorial(int n){ if (n == 0) return 1; return n * factorial(n - 1); } int main(){ int num = 7; cout << "Factorial of " << num << " is " << factorial(num) << endl; return 0; }
输出
Factorial of 7 is 5040
