Write and develop algorithms

[jjspikejones]

I have many errors in this program will someone help I also have to put another for loop the the isRightprime var.

// imports
#include <iostream>
int isRightPrime(int);
int isPrime(int);

// begin main
int main()
{
 // declare variables 
	int rightPrime;
	int Prime;
	int x;
	int y;

using namespace std;  //using namespace system;


int isPrime(long num) // Returns 1 (true) if its prime, or 0 (false) if not
{
if (num < 2) // 1 is not a prime number
return 0;

// if it is > 2 and an even number, then it definitely is not a prime
if (num > 2 && (num % 2) == 0)
return 0;

//considering the fact all can be divided by 1 and itself,
//start checking if there is any other divisor, if found one then no need to continue, it is not a prime
for(int i = 2; i < num; i++ )
{
cout << " divisor: " << i << endl;
if ( (num % i) == 0) // if it is divisible by i
{
// a divisor other than 1 and the number itself
return 0; // no need for further checking
}
}


return 1; // if all hurdles/checks are crossed, heyyyy, its a prime
}

int main()
{
int num;
do {
cout << " enter a number (0 to stop) " << endl;
cin >> num;
if (num) {
if (isPrime(num))
cout << num << " is a prime numebr " << endl;
else
cout << num << " is NOT a prime numebr " << endl;
}
} while (num > 0);

return 0;
}
}

[VernonDozier]

I just helped someone via PM (I know, not supposed to do that ;)). The same post applies here, so I'll recreate it verbatim.

Here's the way it works.

// #include statements
using namespace std;

// function declarations (include semicolons)

int main()
{
    // function calls
    return 0;
}

// functions (copy what's before main, delete semicolons)

Here's an example

#include <iostream>
using namespace std;

int add(int num1, int num2);
int subtract(int num1, int num2);


int main()
{
  int num1 = 5;
  int num2 = 2;
  int num3 = 8;
  int num4 = 4;

  int num5 = add(num1, num2);
  int num6 = subtract(num3, num4);

  cout << num1 << " + " << num2 << " = " << num5 << endl;
  cout << num3 << " - " << num4 << " = " << num6 << endl;
  return 0;
}


int add(int num1, int num2)
{
    int sum = num1 + num2;
    return sum;
}


int subtract(int num1, int num2)
{
    int difference = num1 - num2;
    return difference;
}

Use the above program as a guide for your code. You have functions within functions, which is a no-no, and you have two main functions, which makes no sense at all. You need to have one and only one main function.