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Leetcode 717: 1-bit and 2-bit Characters

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

 1 public class Solution {
 2     public bool IsOneBitCharacter(int[] bits) {        
 3         // Optimization: if the last bit is not 0, return false immediately
 4         if (bits[bits.Length - 1] != 0) return false;
 5         
 6         int
i = 0; 7 while (i < bits.Length) 8 { 9 if (bits[i] == 1) 10 { 11 i += 2; 12 } 13 else if (i == bits.Length - 1) 14 { 15 return true; 16 } 17 else 18 { 19 i++; 20 } 21 } 22 23 return false; 24 } 25 26 }

Leetcode 717: 1-bit and 2-bit Characters