1-bit and 2-bit Characters

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.


这题说数组中最后一个数字为0，问最后一个字符是不是one-bit-character。因为0就是one-bit-character,10是two-bit-character。所以判断最后一个数字0前面连续1有多少个，

class Solution {
    public boolean isOneBitCharacter(int[] bits) {
        int len=bits.length;
        if(len==1)
            return true;
            
        if(bits[len-2]==0)
            return true;
        else{
            int k=1;//从倒数第二个字符开始，连续1的个数
            int i=len-3;
            while(i>=0){
                if(bits[i]==1)
                    k++;
                else
                    break;
                i--;
            }
            if(k%2==0)
                return true;
            else
                return false;
        }
    }
}