[Level1] 달리기 경주 (C++)

#include <string>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;

vector<string> solution(vector<string> players, vector<string> callings) {
    map<string, int> nameMap;
    map<int, string> rankMap;
    
    int idx = 0;
    for(auto player : players) {
        nameMap[player] = idx;
        rankMap[idx] = player;
        idx++;
    }
    
    vector<string> answer = players;
    for(auto player : callings) {
        // 호명한 선수의 현재 등수
        int grade = nameMap[player]; 
        // 앞섰던 선수의 이름
        string name = rankMap[grade-1];
        
        answer.at(grade-1) = player;
        answer.at(grade) = name;
        
        swap(nameMap[player], nameMap[name]);
        swap(rankMap[grade-1], rankMap[grade]);
    }
    
    return answer;
}