Saturday, November 16, 2013

Sum of first 250 prime numbers


In math, a prime number is a number only divisible by 1 and itself.

Given the first few prime numbers2 3 5 7 11 13 17 ...

What is the sum of the first 250 prime numbers? Note that you are seeing the first 7 primes above.

Language C++:

#include<iostream>
using namespace std;

class prime {
       private:
              unsigned int sum_prime;
       public:
              prime() {
              sum_prime = 2;
              }
              void sum_of_primes_calc() { 
                          int pcounter = 1;
                          int num = 3;
                          int i,counter = 0;
                          while(pcounter != 250) {
                                   for (i = 2 ; i < num ; i++) { 
                                               if((num % i) == 0) {
                                                       counter++;
                                                }
                                    }
                                    if(counter == 0) { 
                                            sum_prime += num;
                                            pcounter++;
                                    }
                                    counter = 0;
                                    num++;
                           }
                           cout<<sum_prime<<endl;
              }
};

int main() {
        prime obj;
        obj.sum_of_primes_calc();
        return(0);
}

Output:
182109

Note: To find the sum of primes beyond 250, just change the value in while condition "While(pcounter  !=  250)"

By +Dixit Singla 
Post a Comment