# KCS151/KCS251 PPS Lab Exercise Program: 21

## LAB Exercise Program: 21

#### KCS151P/KCS251P

##### LAB 5

Write a program to calculate the GCD of given numbers using recursion.

Write a program to convert a decimal number into a binary number.

Write a program to convert a binary number into a decimal number.

##### LAB 6

Write a program to delete duplicate element in a list of 10 elements & display it on screen.

Write a program to merge two sorted arrays & no element is repeated during merging.

Write a program to evaluate the addition of diagonal elements of two square matrixes.

Write a program to find the transpose of a given matrix & check whether it is symmetric or not.

Write a program to print the multiplication of two N*N (Square) matrix.

##### LAB 7

Write a program in C to check whether the given string is a palindrome or not.

Write a program to sort the array of characters (String) in alphabetical order like STRING in GINRST.

Write a program to remove all the blank space from the string & print it, also count the no of characters.

Write a program to store the following string “zero”, “one”, … “five”.
Print the no in words, given in figure as 3205.

##### LAB 8

Write a program to compare two given dates. To store a date uses a structure that contains three members namely day, month, and year. If the dates are equal then display message equal otherwise unequal.

Define a structure that can describe a hotel. It should have the member that includes the name, address, grade, room charge, and the number of rooms.
Write a function to print out the hotel of given grade in order of room charges.

Define a structure called cricket with player name, team name, batting average, for 55 players & 5 teams. Print team-wise list contains names of players with their batting average.

##### LAB 9

Write a C program to copy & count the character content of one file, says a.txt to another file b.txt.

Write a program to take 10 integers from a file and write the square of these integers in another file.

Write a program to read numbers from a file and then write all ‘odd’ numbers to file ODD.txt & all ‘even’ to file EVEN.txt.

Write a program to print all the prime numbers, between 1 to 100 in file prime.txt.

Write the following C program using pointer:
a) To sort the list of numbers through the pointer.
b) To reverse the string through the pointer.

##### LAB 10

Write a program to find the largest no among 20 integers array using dynamic memory allocation.

Using Dynamic Memory Allocation, Write a program to find the transpose of the given matrix.

Write a program to find the factorial of the given number using the command line argument.

Write a program to find the sum of digits of a 5 digit number using the command line argument.

## 21. Write a program to find the sum of digits of a 5 digit number using recursion.

				
/*
File: Prgrm21.c
Date: Jan 17, 2021
Description: Program to find the sum of digits of a 5 digit number using recursion.
*/

#include <stdio.h>

int sum_of_digits (int);

int main (void)
{
int num;
int sum;

//Input number
printf ("Input number: ");
scanf ("%d", &num);

//Fucntion call
sum = sum_of_digits (num);

//Print result
printf ("Sum of digits: %d", sum);

return 0;
};

int sum_of_digits (int num)
{
//Calculate sum of digits
//Base case
if (num <= 9)
return num;
else
//Recursive call
return num % 10 + sum_of_digits (num / 10);
};



### Try it yourself

#### Sample Input and Output

Stdin Inputs:

12345

Sample Result:

Input number: 12345
Sum of digits: 15