<p>Given an integer <code>n</code>, return <em>the number of prime numbers that are strictly less than</em> <code>n</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> n = 10
<strong>Output:</strong> 4
<strong>Explanation:</strong> There are 4 prime numbers less than 10, they are 2, 3, 5, 7.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> n = 0
<strong>Output:</strong> 0
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> n = 1
<strong>Output:</strong> 0
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>0 &lt;= n &lt;= 5 * 10<sup>6</sup></code></li>
</ul>

import math
class Solution:
    def countPrimes(self, n: int) -> int:
        prime = [0] * (n + 1)
        
        def makePrimeTable(number):
            for i in range(2,number+1):
                prime[i] = 1
            
            sqrt = int(math.sqrt(number))
            for i in range(2,sqrt+1):
                if prime[i] != 0:
                    for j in range(i*i,number+1,i):
                        prime[j] = 0
        
        makePrimeTable(n)
        ans = []
        count = 0
        for i in range(2,n):
            if prime[i] == 1:
                print(prime[i],i)
                count+=1
        
        return count




        
55868