[HackerRank][Python] Binary Numbers

Task

Given a base-10 integer, n, convert it to binary (base-2). Then find and print the base-10 integer denoting the maximum number of consecutive 1's n's binary representation. When working with different bases, it is common to show the base as a subscript.

Example

n = 125

The binary representation of decimal number 125 is binary number 1111101. In base 10, there are 5 and 1 consecutive ones in two groups. Print the maximum, 5.

Input Format

A single integer, n.

Constraints

• 1 <= n <= 10^6

Output Format

Print a single base-10 integer that denotes the maximum number of consecutive 1's in the binary representation of n.

#!/bin/python3

import math
import os
import random
import re
import sys

def maxConsecutiveOnes(n):
    #convert n to binary
    binary = bin(n)[2:]
    
    #count consecutive ones
    max_count = 0
    count = 0
    for digit in binary:
        if digit == '1':
            count += 1
        else :
            max_count = max(max_count, count)
            count = 0
    max_count = max(max_count, count)

    return max_count
    
if __name__ == '__main__':
    n = int(input().strip())
    
    result = maxConsecutiveOnes(n)
    
    print(result)

The maxConsecutiveOnes() function takes an integer n as input and returns the maximum number of consecutive ones in the binary representation of n.

The bin() function is used to convert n to a binary string. We then iterate through the string, keeping track of the current count of consecutive ones (count) and the maximum count seen so far (max_count). Whenever we encounter a zero, we update max_count if necessary and reset count to zero. Once we've finished iterating through the string, we update max_count one final time and return it.

In the main block, we simply take input for n, call the maxConsecutiveOnes() function, and print the result.