Convert Binary Number in a Linked List to Integer Python/Java solution

In Python or Java, iterate through the linked list and update an integer variable using result = (result << 1) + node.val. The same logic works across C++, JavaScript, and C#. This approach maintains O(n) time and O(1) space.

How to solve Convert Binary Number in a Linked List to Integer in O(n)?

Traverse the linked list from head to tail while maintaining an integer accumulator. At each node compute result = (result << 1) + node.val. The left shift multiplies the current number by two and appends the next binary digit, producing the decimal value in a single pass.

What is the best approach for Convert Binary Number in a Linked List to Integer?

The best approach uses bit manipulation while traversing the linked list. Start with result = 0, then for each node shift the current result left by one and add the node value. This builds the binary number incrementally in O(n) time and O(1) space.

Is Convert Binary Number in a Linked List to Integer asked at Google/Amazon/Meta?

Binary conversion and linked list traversal problems appear frequently in technical interviews at companies like Amazon, Google, and Meta. This specific problem is commonly used to test understanding of bit manipulation and basic linked list iteration.

What data structure is used in Convert Binary Number in a Linked List to Integer?

The core data structure is a singly linked list where each node stores a binary digit (0 or 1). The algorithm processes nodes sequentially and may optionally use bit manipulation operations to construct the final integer value.

What is the time complexity of Convert Binary Number in a Linked List to Integer?

The optimal solution runs in O(n) time because each node in the linked list is visited exactly once. Space complexity is O(1) when using the bit manipulation approach since no extra data structures are required.

Description Hints 2 Solution Video 7:34

1290. Convert Binary Number in a Linked List to Integer

Q: Is Convert Binary Number in a Linked List to Integer easy or hard?

Convert Binary Number in a Linked List to Integer is classified as an Easy problem with an acceptance rate above 80%. The challenge focuses on recognizing the binary accumulation pattern while traversing a linked list.

Q: How to solve Convert Binary Number in a Linked List to Integer in O(n)?

Traverse the linked list from head to tail while maintaining an integer accumulator. At each node compute result = (result << 1) + node.val. The left shift multiplies the current number by two and appends the next binary digit, producing the decimal value in a single pass.

Q: What is the best approach for Convert Binary Number in a Linked List to Integer?

The best approach uses bit manipulation while traversing the linked list. Start with result = 0, then for each node shift the current result left by one and add the node value. This builds the binary number incrementally in O(n) time and O(1) space.

Q: Is Convert Binary Number in a Linked List to Integer asked at Google/Amazon/Meta?

Binary conversion and linked list traversal problems appear frequently in technical interviews at companies like Amazon, Google, and Meta. This specific problem is commonly used to test understanding of bit manipulation and basic linked list iteration.

Q: What data structure is used in Convert Binary Number in a Linked List to Integer?

The core data structure is a singly linked list where each node stores a binary digit (0 or 1). The algorithm processes nodes sequentially and may optionally use bit manipulation operations to construct the final integer value.

Q: What is the time complexity of Convert Binary Number in a Linked List to Integer?

The optimal solution runs in O(n) time because each node in the linked list is visited exactly once. Space complexity is O(1) when using the bit manipulation approach since no extra data structures are required.

Easy82.3% acceptance10 companies

Given head which is a reference node to a singly-linked list. The value of each node in the linked list is either 0 or 1. The linked list holds the binary representation of a number.

Return the decimal value of the number in the linked list.

The most significant bit is at the head of the linked list.

Example 1:

Input: head = [1,0,1]
Output: 5
Explanation: (101) in base 2 = (5) in base 10

Example 2:

Input: head = [0]
Output: 0

Constraints:

The Linked List is not empty.
Number of nodes will not exceed 30.
Each node's value is either 0 or 1.

Asked at 10 companies

Nutanix Roblox Mathworks Oracle

Cisco

Google Amazon Microsoft Meta Bloomberg

Topics

Linked List Math

Hints open one at a time

Hint 1

Traverse the linked list and store all values in a string or array. convert the values obtained to decimal value.

Hint 2

You can solve the problem in O(1) memory using bits operation. use shift left operation ( << ) and or operation ( | ) to get the decimal value in one operation.

7:34

Still stuck?Read 3 approaches, or watch a walkthrough.

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LanguageLoading editor…

1# Definition for singly-linked list.
2# class ListNode:
3#     def __init__(self, val=0, next=None):
4#         self.val = val
5#         self.next = next
6class Solution:
7    def getDecimalValue(self, head: Optional[ListNode]) -> int:
8        

Starter codePython 3Spaces: 4

Examples

Case 1Case 2

Input

[1,0,1]

Input

[0]

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