How do you solve Convert Binary Number in a Linked List to Integer on LeetCode?

Convert Binary Number in a Linked List to Integer (LeetCode #1290) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n) time complexity and O(1) space complexity. Key insight: Understanding binary representation and bit manipulation is crucial.

What is the brute force solution for Convert Binary Number in a Linked List to Integer?

The brute force approach for Convert Binary Number in a Linked List to Integer is Brute Force, with O(n²) time complexity and O(n) space complexity. We can traverse the linked list and collect the binary digits into a string. Then, we can convert that string to a decimal number. This approach is straightforward but not the most efficient. The optimal Optimal Solution approach improves this to O(n).

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

Convert Binary Number in a Linked List to Integer uses the following concepts: Linked List, Math. The recommended patterns to study are: Bit Manipulation, Linked List Traversal.

What are the interview tips for Convert Binary Number in a Linked List to Integer?

Explain your thought process clearly while coding. Consider both time and space complexity in your solution. Practice converting between binary and decimal to strengthen your understanding.

What are common mistakes when solving Convert Binary Number in a Linked List to Integer?

Confusing binary and decimal representations. Not handling edge cases like a single node correctly.

#1290

Convert Binary Number in a Linked List to Integer

Easy

Linked ListMathBit ManipulationLinked List Traversal

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n)
Space	O(n)	O(1)

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Intuition

Time O(n)Space O(1)

Instead of building a string, we can directly compute the decimal value while traversing the linked list. This uses bit manipulation to build the number efficiently.

⚙️

Algorithm

3 steps

1Step 1: Initialize a variable 'result' to 0.
2Step 2: Traverse the linked list while head is not null.
3Step 3: For each node, shift 'result' left by 1 (multiply by 2) and add the current node's value.

solution.py11 lines

1class ListNode:
2    def __init__(self, val=0, next=None):
3        self.val = val
4        self.next = next
5
6def getDecimalValue(head):
7    result = 0
8    while head:
9        result = (result << 1) | head.val
10        head = head.next
11    return result

ℹ

Complexity note: The time complexity is O(n) because we traverse the linked list once. The space complexity is O(1) since we are using a constant amount of space to store the result.

1Understanding binary representation and bit manipulation is crucial.
2Using bitwise operations can significantly optimize performance.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.