Need Help in C LANGUAGE?

Question

printf("Enter a Number: ");

how will it be able to recognize if it is a prime number or a composite number? our topic is looping. please help me. heres the output i need...

"ENTER A NUMBER:"

then if i enter a number.. the words "YOU ENTERED A PRIME NUMBER" or "YOU ENTERED A COMPOSITE NUMBER" must appear under "ENTER A NUMBER:"

sample output:

Enter a Number: 7

You Entered a Prime Number

please help me...

Answer 1

#include <iostream>

using namespace std;

int main()

{

    int number=0;

    cout << "Enter a number: ";

    cin >> number;

cout << endl;



    if ( number == 2 || number == 3 )

    {

        cout << "You entered a Prime Number";

        return 0;

    }



int i = 2;

    while ( (i <= number/2) && (number%i != 0) )

{

i++;

}



if ( i == number/2 )

cout << "You entered a Prime Number";

else

cout << "You entered a Composite Number";



return 0;

}

Answer 2

Get your number from user and store in testValue (int)

(int) testLimit = testValue / 2

(bool) isPrime=allDone = false

(int) loopDivisor = 2

while (!allDone){

(int) remainder = testValue % loopDivisor

if (remainder==0) isPrime = allDone = true;

if (++loopDivisor>testLimit) allDone=true;

}

print appropriate message based on isPrime