A strong number is a number whose sum of factorials of the individual numbers is equal to the number itself. For example, consider the number 145. In this number 1! + 4! + 5! is equal to the number 145 itself. So, 145 is an example for strong number.
/*Program to find whether a given number is strong number or not*/
#include<stdio.h>
#include<conio.h>
main()
{
int num,tnum,sum;
clrscr();
printf("Enter a positive integer:");
scanf("%d",&num);
tnum = num;
sum = 0;
while(num!=0)
{
sum += fact(num%10);
num = num/10;
}
if(sum==tnum)
{
printf("Given number is a strong number");
}
else
{
printf("Given number is not a strong number");
}
getch();
}
/*Logic to calculate the factorial of individual numbers*/
int fact(int n)
{
int f;
if(n==1)
f=1;
else
f = n*fact(n-1);
return f;
}
Sample input and output:
Enter a positive integer: 145
Given number is a strong number
