1 // Write a static method lg() that takes an int value N as argument and returns the largest int not larger than the base-2 logarithm of N. Do not use Math.

2

3 // g++ lg.cpp -o lg

4

5 #include <cmath>

6 #include <climits>

7 #include <iostream>

8

9 int main( int argc, char **argv ) {

10

11 while ( ! std::cin.eof() ) {

12 int i;

13 std::cin >> i;

14 int lg = 0;

15 while ( (1 << lg) <= i ) {

16 lg++;

17 }

18 lg--;

19 std::cout << "lg(" << i << ") >= " << lg << " actual value is " << log2(i) << std::endl;

20 }

21 }