plz explain

can sum1 explain exactly how this program calculates the number of bits required to store a number(i got it off a tutorial and its aint explainin)

Code:

#include <iostream>
using namespace std;

int main()
{
    int bitsRequired = 1; 
    int largest = 1; 
    int powerOf2 = 2;
    int number;

    cout << "Enter a positive integer: ";
    cin >> number;

    while (number > largest)
    {
        bitsRequired += 1;
        powerOf2 = powerOf2 * 2;
        largest = powerOf2 - 1;
    }

    cout << "To store " << number << " requires ";
    cout << bitsRequired << " bits" << endl;
    
    cin.ignore();
    cin.get();

    return 0;
}

thankz in advance

Well all powers of 2 in binary just have ONE bit set - eg 00100000

A power of 2 minus 1 clears that bit, and sets all the bits to the right to 1, so
00100000 would be 00011111

The loop stops when a largest value is greater than the number you want to represent