717. 1-bit and 2-bit Characters

Posted 2020-10-16 __Meng

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.

把数组划分为0,10,11，判断最后一位是不是单个的0

C++(6ms):

 1 class Solution {
 2 public:
 3     bool isOneBitCharacter(vector<int>& bits) {
 4         int len = bits.size() ;
 5         for (int i = 0 ; i < len ; i++){
 6             if (i == len-1 && bits[i] == 0){
 7                 return true ;
 8             }
 9             if (bits[i] == 1){
10                 i++ ;
11             }
12         }
13         return false ;
14     }
15 };