题解 | 字符串排序

全靠自己写不出来,参考别人的

#include <iostream>
#include <bits/stdc++.h>
using namespace std;

char lowercase(char c)
{
    if(c >=97 && c<=122)
    {
        return c-('a'-'A');
    }
    return c;
}

void processing(string& str)
{
    int n = str.size();
    vector<char> ret(n, '\0');
    map<char, string> dic;
    for(int i=0;i<n;i++)
    {
        char c = str[i];
        if(isalpha(c))
        {
            auto it = dic.find(lowercase(c));
            if(it != dic.end())
            {
                it->second.push_back(c);
            }
            else
            {
                string temp;
                temp.push_back(c);
                dic.emplace(lowercase(c), temp);
            }
        }
        else
        {
            ret[i] = c;
        }
    }

    int i = 0;
    for(auto item : dic)
    {
        for(char ch : item.second)
        {
            while(i<n)
            {
                if(ret[i] == '\0')
                {
                    ret[i] = ch;
                    break;
                }
                i++;
            }
        }
    }
    for(auto e : ret)
    {
        cout << e;
    }
    cout << endl;
}


int main() 
{
    string str;
    getline(cin, str);

    processing(str);
}