lucproblem006.c (838B)
1 /* Write a program to find the factorial value of any number entered 2 through the keyboard. */ 3 /* Let Us C, Chap - 5, Page - 84, Problem 5.2 */ 4 5 #include <stdio.h> 6 int main() 7 { 8 int num, i = 1; 9 long long fact = 1; 10 printf("Enter the number : "); 11 // checking if the input is valid or not 12 if (scanf("%d", &num) != 1) 13 { 14 printf("\nPlease enter a number."); 15 return 1; 16 } 17 // result for the negetive input 18 if (num < 0) 19 { 20 printf("\nFactorial of %d : Undefined", num); 21 return 1; 22 } 23 // Hard codded result for input '0' (zero) 24 if (num == 0) 25 { 26 printf("\nFactorial of 0 : 1"); 27 return 0; 28 } 29 // calculating result 30 while (i <= num) { 31 fact = fact * i; 32 i++; 33 } 34 printf("\nFactorial of %d : %d", num, fact); 35 return 0; 36 }