Leetcode 717 One Bit And Two 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.

Note:

1 <= len(bits) <= 1000.

bits[i] is always 0 or 1.

暴力

i从左到右依次的解码遍历, 若为1则 i = i + 2, is1bit赋值为false, 0则为i = i + 1, is1bit赋值为true. 遍历完后返回is1bit即可

class Solution {
public:
    bool isOneBitCharacter(vector<int>& bits) {
        if(bits.empty() || bits.back() == 1)
        {
            throw string("Invalid BitStream");
        }
        int i = 0;
        bool is1bit;
        while(i < bits.size())
        {
            if(bits[i] == 0)
            {
                is1bit = true;
                i += 1;
            }
            else
            {
                is1bit = false;
                i += 2;
            }
        }
        return is1bit;
    }
};