题解 | #字符串排序#

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

int main() {
    string s;
    while(getline(cin, s))  {
        
        vector<char> ss;
        for(int i = 0; i < s.size(); i++)   {
            if(s[i] >= 'a' && s[i] <= 'z' || s[i] >= 'A' && s[i] <= 'Z') {
                ss.push_back(s[i]);
            }
        }

        stable_sort(ss.begin(), ss.end(), [](const char &a, const char &b){
            int numA = 0, numB = 0;
            if(a >= 'a'  && a <= 'z') numA = a;
            else numA = a+32;
             if(b >= 'a'  && b <= 'z') numB = b;
            else numB = b+32;

            return numA < numB;
        });

        int cnt = 0;
        for(int i = 0; i < s.size(); i++)   {
            if(s[i] >= 'a' && s[i] <= 'z' || s[i] >= 'A' && s[i] <= 'Z') {
                printf("%c", ss[cnt++]);
            }
            else printf("%c", s[i]);
        }
        cout << endl;
    }
}
// 64 位输出请用 printf("%lld")