#include <iostream>
#include <utility>
#include <vector>

using namespace std;

int nimSum(const vector<int>& piles)
{
    int result = 0;
    for (int cherries : piles)
    {
        result ^= cherries;
    }
    return result;
}

bool allEmpty(const vector<int>& piles)
{
    for (int cherries : piles)
    {
        if (cherries != 0)
        {
            return false;
        }
    }
    return true;
}

void printPiles(const vector<int>& piles)
{
    cout << "当前各碗樱桃数：";
    for (int i = 0; i < static_cast<int>(piles.size()); ++i)
    {
        if (i > 0)
        {
            cout << ", ";
        }
        cout << "[" << i + 1 << "]=" << piles[i];
    }
    cout << '\n';
}

pair<int, int> computerMove(const vector<int>& piles)
{
    int sum = nimSum(piles);

    if (sum == 0)
    {
        for (int i = 0; i < static_cast<int>(piles.size()); ++i)
        {
            if (piles[i] > 0)
            {
                return {i, 1};
            }
        }
    }

    for (int i = 0; i < static_cast<int>(piles.size()); ++i)
    {
        int target = piles[i] ^ sum;
        if (target < piles[i])
        {
            return {i, piles[i] - target};
        }
    }

    return {-1, -1};
}

int main()
{
    int n;
    cout << "请输入碗的数量 n：";
    cin >> n;

    vector<int> piles(n);
    cout << "请输入每只碗里的樱桃数：";
    for (int i = 0; i < n; ++i)
    {
        cin >> piles[i];
    }

    cout << "\n计算机先手。\n";

    while (true)
    {
        printPiles(piles);

        int currentSum = nimSum(piles);
        if (currentSum == 0)
        {
            cout << "当前异或和为0，说明这是一个先手必败态；计算机只能任选一步合法操作。\n";
        }

        pair<int, int> move = computerMove(piles);
        int pileIndex = move.first;
        int taken = move.second;

        piles[pileIndex] -= taken;
        cout << "计算机从第" << pileIndex + 1 << "只碗里拿走了" << taken << "颗樱桃。\n";

        if (allEmpty(piles))
        {
            cout << "计算机拿到了最后一颗樱桃，计算机获胜。\n";
            break;
        }

        printPiles(piles);
        cout << "现在轮到你。\n";

        while (true)
        {
            cout << "请输入两整数：碗的编号 和 取走的樱桃数：";

            int chosenPile, removed;
            cin >> chosenPile >> removed;
            --chosenPile;

            bool validPile = 0 <= chosenPile && chosenPile < n;
            bool validTake = validPile && 1 <= removed && removed <= piles[chosenPile];

            if (validTake)
            {
                piles[chosenPile] -= removed;
                break;
            }

            cout << "输入不合法，请重新输入。\n";
        }

        if (allEmpty(piles))
        {
            cout << "你拿到了最后一颗樱桃，你获胜。\n";
            break;
        }
    }

    return 0;
}