1290. Convert Binary Number in a Linked List to Integer

https://leetcode.com/problems/convert-binary-number-in-a-linked-list-to-integer/

JavaScript

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} head
 * @return {number}
 */
var getDecimalValue = function(head) {
    let num = 0
    while (head) {
        num = num * 2 + head.val
        head = head.next
    }
    return num
};

Python

# Definition for singly-linked list.
# class ListNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution(object):
    def getDecimalValue(self, head):
        """
        :type head: ListNode
        :rtype: int
        """
        num = 0
        while head:
            num = num * 2 + head.val
            head = head.next
        return num

Go

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func getDecimalValue(head *ListNode) int {
    num := 0
    for head != nil {
        num = num*2+head.Val
        head = head.Next
    }
    return num
}