Ch 9 lesson 3

//this program finds all the prime numbers betwen 0 and 101

#include <iostream>
#include <math.h>
#include <iomanip>
#include <stdio.h>
using namespace std;

int main ()
{
    int num, divisors, prime=0, count, three, sum, rest;


    for (num=0; num<=101; num++){ // this for loop finds the sum of all numbers between 1 to 101.

        sum=sum+num;

    }

    cout << "This code will show the sum of all integers from 0 to 101: They are  " << sum << endl;

    for (num=0; num<=101; num++){ // this for loop finds all the sum of all multiples of three.

        if (num%3<1){

            three=three+num;

        }

    }

    cout << "This code will find and display of sum of all multiples of three from 0 to 101: They are " << three << endl;

    for (num=0; num<=101; num++){ // this loop finds the sum of all prime numbers between 1 and 101.

        if (num>1){
           count=num;
        }

        for (divisors=2; divisors<num; divisors++){

            rest=num%divisors;
            if (rest<1){  // this is the if statement that makes the added value 0 if the tested number has anny divisors.

               count=0;

            }

        }

        prime=prime+count;
    }

    cout << "This will display the sum of all primes from 0 to 101: they are " << prime << endl;


    return 0;
}