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primeNumberGenerator.cpp
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primeNumberGenerator.cpp
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#include <iostream>
#include <math.h>
#include <ctime>
using namespace std;
int main() {
int start_s = clock();
cout << "start";
int prime[1230] = {3, 5, 7};
int a = 3, count = 0, j = 0, num = 0; //num refers to number of primes between 1 & 100 milion.
for(int i = 9; i <= 100; i = (i + 2)){
if((i % 3 != 0) && (i % 5 != 0) && (i % 7 != 0)){
cout << i << " ";
prime[a] = i;
a++;
num++;
}
}
for(int i = 101; i <= 10000; i = (i + 2)){
YES :count = 0, j = 0;
while(prime[j] * prime[j] <= i){
if(j >= a){
cout << i << " ";
prime[a] = i;
i = (i + 2);
a++;
num++;
goto YES;
}
if(i % prime[j] == 0){
count++;
break;
}
j++;
}
if(count == 0){
cout << i << " ";
prime[a] = i;
a++;
num++;
}
}
for(int i = 10001; i <= 100000000; i = (i + 2)){
YESS :count = 0, j = 0;
while(prime[j] * prime[j] <= i){
if(j >= a){
cout << i << " ";
i = (i + 2);
num++;
goto YESS;
}
if(i % prime[j] == 0){
count++;
break;
}
j++;
}
if(count == 0){
num++;
cout << i << " ";
}
}
cout << "end \n";
int stop_s = clock();
cout << " \n time : " <<(stop_s-start_s)/double(CLOCKS_PER_SEC)<< endl << num << endl;
return 0;
}