help!

[lgill30]

Write a program that contains a menu which allows a user to choose any of the following functions:

• function that asks the user for a number n and prints the sum of the numbers 1 to n

• function that prints the next 20 leap years.

• function that prints all prime numbers. (Note: if your programming language does not support arbitrary size numbers, printing all primes up to the largest number you can represent is fine too.)

• function that prints a multiplication table for a given number n.

[mutexe]

Whatcha got so far?

[lgill30]

nothing. teacher does not know how to teach.

[lgill30]

#include <stdio.h>
#include <conio.h>
using namespace std;

int main()
{
cout << "**************************" << endl;
cout << "1. Sum of number 1 to n" << endl;
cout << "2. Print next 20 years" << endl;
cout << "3. All prime numbers" << endl;
cout << "4. Multiplication table" << endl;
cout << "**************************" << endl;
}



int main()
{
int n;
cout << "Enter n Value: ";
cin >> n;
cout << "The Sum Is: " << prime(n);
}

int prime(int n)
{
int num = 0;
bool prime;
for (int i = 2; i <= n; i++)
{
prime = true;
for (int j = 2; j < i; j++)
{
if (i % j == 0)
{
prime = false;
break;
}
}
if (prime)
{
num += i;
}
}
return num;
}



int leapyear(int yr)
{

if ((yr % 4 == 0) && !(yr % 100 == 0))
cout << yr;
else if (yr % 400 == 0) // year divisible by 4 but not by 100
cout << yr;
return yr;

}

int main()
{
const int arraySize = 5; // arraySize must be const
int year[arraySize]; // declare array for input

cout << "Enter " << arraySize << " four digits years:\n";
for (int i = 0; i < arraySize; i++)
cin >> year[i];

cout << leapyear(year) << " is a leap year.\n" << endl;




}


int primeFactors(int n)
{
// Print the number of 2s that divide n
while (n % 2 == 0)
{
printf("%d ", 2);
n = n / 2;
}

// n must be odd at this point. So we can skip one element (Note i = i +2)
for (int i = 3; i <= sqrt(n); i = i + 2)
{
// While i divides n, print i and divide n
while (n%i == 0)
{
printf("%d ", i);
n = n / i;
}
}

// This condition is to handle the case whien n is a prime number
// greater than 2
if (n > 2)
printf("%d ", n);
}




int main(){

int r, i, j, k;

printf("Enter the number range: ");

scanf("%d", &r);

for (i = 1; i <= r; i++){

for (j = 1; j <= 10; j++)

printf("%d*%d=%d ", i, j, i*j);

printf("\n");

}

return 0;

}