717. 1-bit and 2-bit Characters最后一位数是否为0

[抄题]:

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.

 [暴力解法]:

时间分析:

空间分析:

 [优化后]:

时间分析:

空间分析:

[奇葩输出条件]:

[奇葩corner case]:

[思维问题]:

没见过,不会

[一句话思路]:

正常操作后判断位数能不能对上

[输入量]:空: 正常情况:特大:特小:程序里处理到的特殊情况:异常情况(不合法不合理的输入):

[画图]:

[一刷]:

  1. 用while循环,因为最后要差也就之差了一位

[二刷]:

[三刷]:

[四刷]:

[五刷]:

  [五分钟肉眼debug的结果]:

[总结]:

正常操作后判断位数能不能对上

[复杂度]:Time complexity: O(n) Space complexity: O(1)

[英文数据结构或算法,为什么不用别的数据结构或算法]:

[关键模板化代码]:

直接用能不能对上来返回:

//return, check
        return i == n - 1;

[其他解法]:

[Follow Up]:

[LC给出的题目变变变]:

 [代码风格] :

class Solution {
    public boolean isOneBitCharacter(int[] bits) {
        //ini
        int n = bits.length;
        int i = 0;
        
        //cc
        if (bits == null || n == 0) {
            return false;
        }
        
        //while loop
        while (i < n - 1) {
            if (bits[i] == 0) {
                i++;
            }else {
                i += 2;
            }
        }
        
        //return, check
        return i == n - 1;
    }
}
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原文地址:https://www.cnblogs.com/immiao0319/p/8875094.html