Question

write a c program that asks the user to enter any two intger numbers and each number consist of four digits. your program should check whether the numbers are four digits or not and in case they are not a four digit number the program should print a message and exit otherwise it should do the following print a mnew as follows   

select what you want to do with the number 1-3:

1-print grreatest common divisor (gcd)of the two numbers

2-print sum of odd digits of each number

3-print relation of odd sum of digits larger/smaller/equal

Answer 1

Code:-

#include<stdio.h>
#include<stdlib.h>
//Function to calculate gcd of two numbers
int gcd_of_numbers(int num1, int num2)
{
if (num2 == 0)
return num1;
return gcd_of_numbers(num2, num1 % num2);

}
//function to calculate odd digits sum of number
int odd_digit(int num){
   int odd_sum=0;
   int digit;
   int remainder;
   while(num>0){
       digit=num%10;//stores the each digit of number
       num=num/10;
       remainder=digit%2;//To know whether it is even or odd digit
       if(remainder==1)
           odd_sum+=digit;
   }
   return odd_sum;
}
int main(){

   int num1,num2;//variables for user input
   printf("Enter two integers that contain four digits\n");
   scanf("%d%d",&num1,&num2);
   if((num1>=1000&&num1<=9999) && (num2>=1000 && num2<=9999)){
       printf("Select what you want to do with numbers1-3\n");
       printf("1-print greatest common divisors of two numbers\n");
       printf("2-print sum of digits of each number\n");
       printf("3-print relation of odd sum of digits larger/smaller/equal\n");
       int choice;//variable for choosing option
      
       int odd_digit_sum_number1;
       int odd_digit_sum_number2;
       scanf("%d",&choice);
       switch(choice){
           case 1: printf("gcd of given two numbers is :%d\n",gcd_of_numbers(num1,num2));
                   break;
           case 2:printf("Sum of odd digits of first number: %d\n",odd_digit(num1));
                   printf("Sum of odd digits of second number: %d\n",odd_digit(num2));
                   break;
           case 3:
                   odd_digit_sum_number1=odd_digit(num1);//Call the function and store result in this variable
                   odd_digit_sum_number2=odd_digit(num2);
                   if(odd_digit_sum_number1>odd_digit_sum_number2)
                       printf("Number 1 odd digits sum= %d is larger than Number 2 odd digits sum= %d\n",odd_digit_sum_number1,odd_digit_sum_number2);
                   else if(odd_digit_sum_number1<odd_digit_sum_number2)
                       printf("Number 1 odd digits sum= %d is smaller than Number 2 odd digits sum= %d\n",odd_digit_sum_number1,odd_digit_sum_number2);
                   else
                       printf("Number 1 odd digits sum= %d is equal to Number 2 odd digits sum= %d\n",odd_digit_sum_number1,odd_digit_sum_number2);
                   break;
           default:
                   printf("Invalid Option");
       }
   }
   else{
       printf("The given user input does not contain four digits\n");
       exit(0);
   }

   return 0;
}

Output:-

Code Image:-