Strong Number in C

Example

Input

Input number: 145

Output

145 is STRONG NUMBER

Required knowledge

Basic C programming, If else, For loop, While loop, Nested loop

What is Strong number?

Strong number is a special number whose sum of factorial of digits is equal to the original number.
For example: 145 is strong number. Since, 1! + 4! + 5! = 145

Logic to check Strong number

Step by step descriptive logic to check strong number.

1. Input a number from user to check for strong number. Store this in a variable say num. Copy it to a temporary variable for calculations purposes, say originalNum = num.
2. Initialize another variable to store sum of factorial of digits, say sum = 0.
3. Find last digit of the given number num. Store the result in a variable say lastDigit = num % 10.
4. Find factorial of lastDigit. Store factorial in a variable say fact.
5. Add factorial to sum i.e. sum = sum + fact.
6. Remove last digit from num as it is not needed further.
7. Repeat steps 3 to 6 till num > 0.
8. After loop check condition for strong number. If sum == originalNum, then the given number is Strong number otherwise not.

Learn more - Program to find sum of digits of number.