//
// Created by PC on 25-8-11.
//

#ifndef WINNERTREE_H
#define WINNERTREE_H
#include <algorithm>
#include <iostream>
#include <deque>

template <class T>
class winnerTree {
private:
    std::deque<T> data;
    int playerNum;
    bool isInit = false;
public:
    winnerTree() : playerNum(0) {}
    winnerTree(const std::deque<T>& d,int playerNum) : playerNum(playerNum), data(d) {}
    ~winnerTree() = default;

    void init();
    int winner();
    void replay(const T& player, const T& alter);
    void display();
};

template<class T>
void winnerTree<T>::init() {
    for (int i = 0; i < 2 * playerNum - 2; i+=2) {
        T max = std::min(data.at(i), data.at(i + 1));
        data.push_back(max);
    }
    std::reverse(data.begin(), data.end());
    isInit = true;
}

template<class T>
int winnerTree<T>::winner() {
    if (!isInit) {
        std::cout << "Uninitialized!" << std::endl;
        return -1;
    }
    return data.front();
}

template<class T>
void winnerTree<T>::replay(const T &player, const T &alter) {
    int index = -1;
    // 查找叶子节点（可改为用player id更稳妥）
    for (int i = data.size() - playerNum; i < data.size(); i++) {
        if (data[i] == player) {
            data[i] = alter;
            index = i;
            break;
        }
    }
    if (index == -1) {
        std::cout << "No such player!" << std::endl;
        return;
    }
    // 向上调整父节点
    while (index > 0) {
        int parent = (index - 1) / 2;
        int against = (index % 2 == 0) ? index - 1 : index + 1;

        // 判断against是否越界
        if (against >= data.size()) against = index; // 没对手时自己跟自己比

        T maxVal = std::min(data.at(index), data.at(against));

        if (data.at(parent) == maxVal) {
            break; // 父节点胜者不变，提前结束
        }
        data.at(parent) = maxVal;
        index = parent;
    }
}


template<class T>
void winnerTree<T>::display() {
    int cnt = 1;
    int jmp = 1;
    for (int i = 0; i < data.size(); ++i) {
        cnt--;
        std::cout << data.at(i) << " ";
        if (cnt == 0) {
            std::cout << std::endl;
            jmp *= 2;
            cnt = jmp;
        }
    }
}
#endif //WINNERTREE_H