题解 | #字符逆序#

还可以一行：reverse(s.begin(),s.end()) 也可以双指针

#include<iostream>
#include<string>
using namespace std;
int main(void)
{
    string s;
    getline(cin,s);
    string res;
    for(int i = s.size()-1;i >=0;i--)
    {
        res.push_back(s[i]);
    }
    cout<<res<<endl;
    return 0;
}
//双指针
#include<iostream>
#include<string>
using namespace std;
int main(void)
{
    string s;
    getline(cin,s);
    int left = 0;
    int right = s.size()-1;
    while(left < right)
    {
        swap(s[left++], s[right--]);
    }
    cout<<s<<endl;
}