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Convert Binary Number in a Linked List to Integer - Linked List - Easy - LeetCode - MiniTV

Convert Binary Number in a Linked List to Integer - Linked List - Easy - LeetCode - मिनी टीवी

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.

 

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
Example 3:

Input: head = [1]
Output: 1
Example 4:

Input: head = [1,0,0,1,0,0,1,1,1,0,0,0,0,0,0]
Output: 18880
Example 5:

Input: head = [0,0]
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.

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     public int val;
 *     public ListNode next;
 *     public ListNode(int val=0, ListNode next=null) {
 *         this.val = val;
 *         this.next = next;
 *     }
 * }
 */
public class Solution {
    public int GetDecimalValue(ListNode head) {
        int len=0;
        ListNode temp = head;
        while(temp!=null){
            len++;
            temp = temp.next;
        }
        
        int res = 0;
        while(head!=null){
            if(head.val==1){
                res+=(int)Math.Pow(2,len-1);
            }
            head = head.next;
            len--;
        }
        
        return res;
    }
}

Time Complexity: O(n)

Space Complexity: O(1)