力扣-1047题删除字符串中的所有相邻重复项（C++）- 有点诡异&& tell me why

待我称王封你为后i 2022-08-28 13:49 177阅读 0赞

题目链接：[https://leetcode-cn.com/problems/remove-all-adjacent-duplicates-in-string/][https_leetcode-cn.com_problems_remove-all-adjacent-duplicates-in-string]  
题目如下：  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASkluZ2xlczEyMw_size_20_color_FFFFFF_t_70_g_se_x_16]  
很诡异，注意两个解法的代码和执行时间  
解一：  
![在这里插入图片描述][a12e3aa936f64362b54cdb6b25c45d99.png]

class Solution {
        
    public:
        string removeDuplicates(string s) {
        
            stack<char> stk;
    
            for(auto e:s){
        
                if(!stk.empty()&&e==stk.top()) stk.pop();
                else stk.push(e);
            }
    
            string result="";
            while(!stk.empty()){
        
                result+=stk.top();
                stk.pop();
            }
            reverse(result.begin(),result.end());
    
            return result;
        }
    };

解二：同一份代码提交，代码如下，和解法一差别不大  
![在这里插入图片描述][watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASkluZ2xlczEyMw_size_20_color_FFFFFF_t_70_g_se_x_16 1]

class Solution {
        
    public:
        string removeDuplicates(string s) {
        
            stack<char> stk;
    
            for(auto e:s){
        
                if(!stk.empty()&&e==stk.top()) stk.pop();
                else stk.push(e);
            }
    
            string result="";//不能使用原来的string s，应新建一个result的string
            while(!stk.empty()){
        
        
                result=stk.top()+result;
                stk.pop();
            }
            
            return result;
        }
    };

# WHO CAN TELL ME WHY！！！ #

[https_leetcode-cn.com_problems_remove-all-adjacent-duplicates-in-string]: https://leetcode-cn.com/problems/remove-all-adjacent-duplicates-in-string/
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASkluZ2xlczEyMw_size_20_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/f58369dfdf9a4769929e909baf3250de.png
[a12e3aa936f64362b54cdb6b25c45d99.png]: /images/20220828/8cbf7ebc2e324b9daad18e42595c5552.png
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBASkluZ2xlczEyMw_size_20_color_FFFFFF_t_70_g_se_x_16 1]: /images/20220828/39b51f91742e45bf87c1d902b5828c24.png