Question

answer the following using C#

Design and program a Visual Studio Console project in C# that allows your user to enter a number. The program will examine the number to see if it is prime. If it is prime, it will print the next higher prime and the next lower primes to the console. If the number entered by the user is not prime, display a message to that effect.

All code should be written by you. Do not copy/paste any code from any other source.

Assume the input will be within the range 2 to (2^{^31}-1)

You should not validate the user input.

Answer 1

I have uploaded the Images of the code, Typed code and Output of the Code. I have provided explanation using comments (read them for better understanding).

Images of the Code:
1 // using Systems 2 using System; 3 class Primes 4-{ 5 // A method named is_prime to determine Prime or Not 6 // with input parameters n 7 static int is_prime(int n) 8 { 9 // A variable to store factors count 10 int count=0; 11 // Finding the factors of n 12 for(int i=1;i<=n;i++) 13 { 14 // if n is divisible by i 15 if(n%i == 0) 16 { 17 // incrementing factors count 18 count++; 19 } 20 } 21 // if factors count is 2 22 if(count 2) 23- { 24 // returning 1 25 return 1; 26 } 27 else // otherwise 28 { 29 // returning 0 30 return 0; 31 } 32 } 33 34 // Main method 35 static void Main() 36 { 37 // A variable to store user input ==

int number=0; // Prompting for input Console.WriteLine("Enter a Number:"); // reading input from user number = Convert.ToInt32(Console.ReadLine()); // Calling the method is_prime with user input number if(is_prime (number)==1) { // if the user input is Prime number Console.WriteLine(number+" is a Prime number"); // A variable to Store Lower Prime number // initializing it with number - 1 int Lower = number - 1; I/ A variable to Store Higher Prime number // initializing it with number - 1 int Higher = number + 1; 38 39 40 41 42 43 44 45 - 46 47 48 49 50 51 52 53 54 55 56 57 - 58 59 60- 61 62 63 64 65 66 67 68 69 70 71 72 73 - 74 75 // Finding the possible Lower Prime number while(Lower>2) { // Calling method is_prime if(is_prime (Lower) ==1) { // if Lower value is a Prime number // printing Lower value Console.WriteLine("The Lower Prime of "+number+ // break the loop break; } // decrementing Lower value Lower--; } 11 is +Lower); // Finding the possible Higher Prime number while(Higher > 2) { // Calling method is_prime if(is_prime (Higher) 1)

is + Higher); { // if Higher value is a Prime number // printing Higher value Console.WriteLine("The Higher Prime of "+number+ " // break the loop break; } // incrementing Higher value Higher ++ ; 76 - 77 78 79 80 81 82 83 84 85 86 87 88- 89 90 91 92 93 94 95} } else { // if user input is not a prime number // printing a Message not a a prime Console.WriteLine(number + " is Not a Prime Number"); }

Note: If the below code is missing indentation please refer code Images

Typed Code:

// using Systems
using System;
class Primes
{
// A method named is_prime to determine Prime or Not
// with input parameters n
static int is_prime(int n)
{
// A variable to store factors count
int count=0;
// Finding the factors of n
for(int i=1;i<=n;i++)
{
// if n is divisible by i
if(n%i == 0)
{
// incrementing factors count
count++;
}
}
// if factors count is 2
if(count == 2)
{
// returning 1
return 1;
}
else // otherwise
{
// returning 0
return 0;
}
}
  
// Main method
static void Main()
{
// A variable to store user input
int number=0;
// Prompting for input
Console.WriteLine("Enter a Number:");
// reading input from user
number = Convert.ToInt32(Console.ReadLine());
// Calling the method is_prime with user input number
if(is_prime(number)==1)
{
// if the user input is Prime number
Console.WriteLine(number+" is a Prime number");
// A variable to Store Lower Prime number
// initializing it with number - 1
int Lower = number - 1;
// A variable to Store Higher Prime number
// initializing it with number - 1
int Higher = number + 1;
  
// Finding the possible Lower Prime number
while(Lower>2)
{
// Calling method is_prime
if(is_prime(Lower)==1)
{
// if Lower value is a Prime number
// printing Lower value
Console.WriteLine("The Lower Prime of "+number+ " is " +Lower);
// break the loop
break;
}
// decrementing Lower value
Lower--;
}
  
// Finding the possible Higher Prime number
while(Higher > 2)
{
// Calling method is_prime
if(is_prime(Higher) == 1)
{
// if Higher value is a Prime number
// printing Higher value
Console.WriteLine("The Higher Prime of "+number+ " is " + Higher);
// break the loop
break;
}
// incrementing Higher value
Higher ++ ;
}
}
else
{
// if user input is not a prime number
// printing a Message not a a prime
Console.WriteLine(number + " is Not a Prime Number");
}
  
}
}
//code ended here

Output:

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Enter a Number: 5 5 is a Prime number The Lower Prime of 5 is 3 The Higher Prime of 5 is 7

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