刷题了：344.反转字符串|541. 反转字符串II|卡码网：54.替换数字

344.反转字符串

题目链接:https://leetcode.cn/problems/reverse-string/description/
文章讲解:https://programmercarl.com/0344.%E5%8F%8D%E8%BD%AC%E5%AD%97%E7%AC%A6%E4%B8%B2.html
视频讲解:https://www.bilibili.com/video/BV1fV4y17748/?spm_id_from=333.788&vd_source=e70917aa6392827d1ccc8d85e19e8375
实现情况：

class Solution {
public:
    void reverseString(vector<char>& s) {
        for(int  i = 0,j = s.size()-1; i<s.size()/2;i++,j--){
            swap(s[i],s[j]);
        }

    }
};

541. 反转字符串II

题目链接:https://leetcode.cn/problems/reverse-string-ii/description/
文章讲解:https://programmercarl.com/0541.%E5%8F%8D%E8%BD%AC%E5%AD%97%E7%AC%A6%E4%B8%B2II.html
视频讲解:https://www.bilibili.com/video/BV1dT411j7NN/?spm_id_from=333.1007.top_right_bar_window_history.content.click&vd_source=e70917aa6392827d1ccc8d85e19e8375
实现情况：

class Solution {
public:
    string reverseStr(string s, int k) {
        for (int i = 0; i < s.size(); i += (2 * k)) {
            if (i + k < s.size()) {
                reverse(s.begin() + i, s.begin() + i + k);
            } else {
                reverse(s.begin() + i, s.end());
            }
        }
        return s;
    }
};

卡码网：54.替换数字

题目链接:https://kamacoder.com/problempage.php?pid=1064
文章讲解:https://programmercarl.com/kama54.%E6%9B%BF%E6%8D%A2%E6%95%B0%E5%AD%97.html

实现情况：
主要格式注意

#include <iostream>
#include <vector>  
#include <string> 
using namespace std;


int main(void){
    string s;
    cin>>s;
    vector<char> result;
        for(char c:s){
            if(c <='z'&& c>='a'){
                result.push_back(c);
            }else{
                for(char nc:string("number")){
                    result.push_back(nc);
                }
            }
        }
    cout << string(result.begin(), result.end());
    
}