Kavita ma'am - 1st question

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <bits/stdc++.h>

using namespace std;

unordered_map<string, int> memo;

// returns {0, 1} as per if A or B wins.
int solve(int n, int currPlayer) {
    string key = to_string(n) + "|" + to_string(currPlayer);

    if(memo.count(key)) return memo[key];

    if(n==0) {
        // currPlayer loses
        memo[key] = !currPlayer;
        return !currPlayer;
    }
    int option1 = !currPlayer, option2 = !currPlayer, option3 = !currPlayer;
    if (n>=1) {
        // currPlayer can take 1 item
        option1 = solve(n-1, !currPlayer);
    }

    if (n>=2) {
        option2 = solve(n-2, !currPlayer);
    }

    if (n>=4) {
        option3 = solve(n-4, !currPlayer);
    }

    if(option1 == currPlayer || option2 == currPlayer || option3 == currPlayer) {
        memo[key] = currPlayer;
    }
    else {
        memo[key] = !currPlayer;
        return !currPlayer;
    }

    return memo[key];
}

int main() {
    int T; cin >> T;

    while(T--) {
        int n; cin >> n;
        int answer = solve(n, 0);
        if(answer == 0) cout << "A" << endl;
        else cout << "B" << endl;
    }

    return 0;
}