# C++ Program to Implement Sieve of eratosthenes to Generate Prime Numbers Between Given Range

C++Server Side ProgrammingProgramming

This is C++ program to implement Sieve of Eratosthenes to Generate Prime Numbers Between Given Range. In this method, an integer array with all elements initializes to zero.

It follows where each non-prime element’s index is marked as 1 inside the nested loops. The prime numbers are those whose index is marked as 0.

## Algorithm

Begin
Declare an array of size n and initialize it to zero
Declare length, i, j
For i = 2 to n-1 do
For j = i*i to n-1 do
Arr[j-1]=1
Done
Done
For i =1 to n do
If(arr[i-1]==0)
Print i
Done
End

## Example Code

#include <iostream>
const int len = 30;
int main() {
int arr[30] = {0};
for (int i = 2; i < 30; i++) {
for (int j = i * i; j < 30; j+=i) {
arr[j - 1] = 1;
}
}
for (int i = 1; i < 30; i++) {
if (arr[i - 1] == 0)
std::cout << i << "\t";
}
}

## Output

1 2 3 5 7 11 13 17 19 23 29
Published on 15-Mar-2019 06:55:58