254C - Anagram - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
#define lol long long
#define l '\n'
#define M7md std::ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);

int main() {
    M7md//When I wrote this code, only God and I understood what I did. Now only God knows//
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    string X,Y;
    cin>>X>>Y;
    vector<int>L(26),R(26);
    for(auto j:X){
        L[j-'A']++;
    }
    for(auto j:Y){
        R[j-'A']++;
    }
    vector<int>S(26),P;
    int SS=0;
    for(int j=0;j<26;j++){
        if(R[j]>L[j]) {
            for(int k=0;k<abs(L[j]-R[j]);k++){
                P.push_back(j);
            }
            SS+=abs(L[j]-R[j]);
        }
        
    }
    cout<<SS<<"\n";
    SS=0;
    for(int j=0;j<X.size();j++){
        int chart=X[j]-'A';
        if(R[chart]<L[chart]){
            if(P[SS]<=chart||L[chart]-S[chart]==L[chart]-R[chart]){
              X[j]=char(P[SS]+'A');
               --L[chart];
               ++L[P[SS]];
               ++SS;
            }
            else
              S[chart]++;
        }
        else
          S[chart]++;
    }
    cout<<X;



}