#include <iostream>
#include <random>
#include <cstdlib>
#include <conio.h>
using namespace std;

const int Boardlength=4;
int board[Boardlength][Boardlength]={2,4,16,2,4,32,64,8,4,16,128,8,2,4,32,2};
random_device rd;

void Rand()
{
    uniform_int_distribution<int> dist(0,Boardlength*Boardlength-1);
    int randcol,randrow;
    while(true){
        int randboard=dist(rd);
        randcol=randboard%Boardlength;
        randrow=randboard/Boardlength;
        if(board[randrow][randcol]==0) break;
    }
    uniform_int_distribution<int> dist2(1, 2);
    int randnumber=dist2(rd)*2;
    board[randrow][randcol]=randnumber;
}

void Clockwise()
{
    int rotaboard[Boardlength][Boardlength];
    for(int i=0;i<Boardlength;i++){
        for(int j=0;j<Boardlength;j++){
            rotaboard[j][Boardlength-1-i]=board[i][j];
        }
    }
    for(int i=0;i<Boardlength;i++){
        for(int j=0;j<Boardlength;j++){
            board[i][j]=rotaboard[i][j];
        }
    }
}

void MoveUp() {
    bool merged[Boardlength][Boardlength] = {}; // 追踪已合并的格子
    for (int i = 0; i < Boardlength; i++) {
        for (int j = 0; j < Boardlength; j++) {
            if (board[j][i] != 0) {
                int k = j;
                while (k > 0 && board[k - 1][i] == 0) {
                    board[k - 1][i] = board[k][i]; // 向上移动
                    board[k][i] = 0;
                    k--;
                }
                if (k > 0 && board[k - 1][i] == board[k][i] && !merged[k - 1][i]) {
                    board[k - 1][i] *= 2; // 合并
                    board[k][i] = 0;
                    merged[k - 1][i] = true; // 标记已合并
                }
            }
        }
    }
    Rand(); // 合并后生成新数字
}


void MoveDown()
{
    Clockwise();
    Clockwise();
    MoveUp();
    Clockwise();
    Clockwise();
}

void MoveRight()
{
    Clockwise();
    Clockwise();
    Clockwise();
    MoveUp();
    Clockwise();
}

void MoveLeft()
{
    Clockwise();
    MoveUp();
    Clockwise();
    Clockwise();
    Clockwise();
}

void DisplayBoard()
{
    system("cls"); // 清屏
    cout<<"通过上下左右方向键来控制，按q退出游戏，按a显示简介"<<endl;
    for (int i=0;i<Boardlength;i++){
        for (int j=0;j<Boardlength;j++){
            cout<<board[i][j]<<"\t";
        }
        cout<<endl;
    }
}

bool Isfull()
{
    for(int i=0;i<Boardlength;i++){
        for(int j=0;j<Boardlength;j++){
            if(board[i][j]==0) return false;
        }
    }
    return true;
}


bool IsfullbutCanMoveCol()
{
    if(Isfull()){
        for(int i=0;i<Boardlength;i++){
            for(int j=0;j<Boardlength;j++){
                if(j<Boardlength-1 && board[i][j]==board[i][j+1]) return true;
            }
        }
        return false;
    }
    else return false;
}

bool IsfullbutCanMoveRow()
{
    if(Isfull()){
        for(int i=0;i<Boardlength;i++){
            for(int j=0;j<Boardlength;j++){
                if(i<Boardlength-1 && board[i][j]==board[i+1][j]) return true;
            }
        }
        return false;
    }
    else return false;
}


int main(){
    char a;
    cout<<"2048小游戏"<<endl;
    cout<<"通过上下左右方向键来控制,按q退出游戏"<<endl;
    cout<<"点击任意键开始游戏"<<endl;
    a=getch();
    while(true){
        Rand();
        Rand();
        DisplayBoard();
        while(true){
            a=getch();
            if(Isfull){cout<<"ok"<<endl;}
            if(Isfull()){
                if(IsfullbutCanMoveCol&&!IsfullbutCanMoveRow){
                    if(a==75 || a==77){
                            cout<<"No doing this step"<<endl;
                            cout<<"点击任意键继续游戏"<<endl;
                            a=getch();
                            goto there;
                    }
                }
                if(IsfullbutCanMoveRow&&!IsfullbutCanMoveCol){
                    if(a==72 || a==80){
                            cout<<"No doing this step"<<endl;
                            cout<<"点击任意键继续游戏"<<endl;
                            a=getch();
                            goto there;
                    }
                }
                if(!IsfullbutCanMoveCol()&&!IsfullbutCanMoveRow()){
                    cout<<"Game Over"<<endl;
                    break;
                }
            }
            //上：72 下：80 左：75 右：77
            if(a==72) MoveUp();
            if(a==80) MoveDown();
            if(a==75) MoveLeft();
            if(a==77) MoveRight();
            if(a=='q') break;
            there:
            DisplayBoard();

        }
        cout<<"如果要再玩一次游戏,请输入123"<<endl;
        string response;
        cin>>response;
        if(response!="123") break;
        fill(&board[0][0],&board[0][0]+sizeof(board)/sizeof(int),0);
    }
    return 0;
}