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Leetcode
Easy
Linked Lists
Arrays
Math
Convert Binary Number In A Linked List To Integer

Convert a binary number stored in a linked list into its decimal integer value.

Acceptance 82%
Problem Statement

Convert Binary Number in a Linked List to Integer

You are given the head of a singly linked list where each node contains either 0 or 1. The linked list represents a binary number, with the most significant bit at the head of the list and the least significant bit at the tail.

Write a function that returns the decimal integer value of the binary number represented by the linked list.

For example, the list 1 -> 0 -> 1 represents binary 101, which is decimal 5.

Input Format

  • A singly linked list head node.
  • Each node stores one binary digit: 0 or 1.

Output Format

  • Return the integer value of the binary number encoded by the list.

Constraints

  • The linked list contains at least one node.
  • Each node value is either 0 or 1.
  • The length of the list is small enough that the answer fits in a standard integer type.

Hints

  • Traverse the list once while building the answer.
  • When you move to the next bit, the current value can be shifted left by 1 before adding the new digit.

Input Format

A singly linked list head node where each node contains a binary digit (0 or 1).

Output Format

Return the decimal integer value represented by the linked list.

Constraints

  • At least one node is present.
  • Node values are only 0 or 1.
  • The final answer fits in a standard integer type.
Examples
Sample cases returned by the problem API.

Example 1

Input

head = [1,0,1]

Output

5

Explanation

Binary 101 equals decimal 5.

Example 2

Input

head = [0]

Output

0

Explanation

Binary 0 equals decimal 0.

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