Week 3 : Assignments - NPTEL >> Introduction to Programming In C - 2025

Week 3 : Assignment 3 - Question 1

Write a program that reads N integers one by one and prints the largest among them.

Solution :

#include<stdio.h>
int main()
{
  char c,shift;
  scanf("%c",&c);
  shift = c + 3;
  if(shift > 'z')
  {
    shift = shift-'z' + 'a' -1;
  }
  printf("%c",shift);
  return 0;
}

Week 3 : Assignment 3 - Question 2

Complete the function int is prime(int n) to check if a positive number n is prime or not.

Solution :

#include<stdio.h>
// Complete this function to check if a number is prime
// Return 1 if n is prime 0 if not

int is_prime(int n) {
  	if (n <= 1) {
        return 0;
    }
    for(int i=2;i<=n/2;i++)
    {
      if(n%i==0)
        return(0);
    }
   return(1);
}

int main() {
    int n, num;
    scanf("%d", &n);
  
    int flag = 0;
  
    for (int i = 0; i < n; i++) {
        
      scanf("%d", &num);
        
      if (is_prime(num)) {
          
          if(flag == 0){
            	printf("%d", num);
      			flag = 1;     
          }
          else{
            printf(" %d", num);
          }
          
        }
    }

    return 0;
}

Week 3 : Assignment 3 - Question 3

Write a C program that takes a single lowercase English letter as input and shifts it three positions forward in the alphabet using the Caesar cipher technique.

Solution :

#include<stdio.h>
int main()
{
  char c,shift;
  scanf("%c",&c);
  shift = c + 3;
  if(shift > 'z')
  {
    shift = shift-'z' + 'a' -1;
  }
  printf("%c",shift);
  return 0;
}