Question

We have two special characters. The first character can be represented by one bit 0. The second character can be represented by two bits (10 or 11).

Now given a string represented by several bits. Return whether the last character must be a one-bit character or not. The given string will always end with a zero.

Example 1:

Input: 
bits = [1, 0, 0]
Output: True
Explanation: 
The only way to decode it is two-bit character and one-bit character. So the last character is one-bit character.

Example 2:

Input: 
bits = [1, 1, 1, 0]
Output: False
Explanation: 
The only way to decode it is two-bit character and two-bit character. So the last character is NOT one-bit character.

Note:

  1. 1 <= len(bits) <= 1000.
  2. bits[i] is always 0 or 1.

Solutions:

  • Method 1: Array 7m50s 
      class Solution {
      public boolean isOneBitCharacter(int[] bits) {
          int index = 0;
          while(index < bits.length){
              if(index == bits.length - 1) return true;
              if(bits[index] == 0) index++;
              else index += 2;
          }
          return false;
      }
  }