代码来源：冯天笑

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iomanip>
//#include <termio.h>
#include "windows.h"
#include <conio.h> 
using namespace std;

const int BLACK = 1;
const int WHITE = -1;
const int INF = 100000000;
int num[10][10]; // 值为0表示没有值，非0表示有数据，越界为正无穷
int rd = 0; // 回合数
int pos = 1; // 所在列
int color = BLACK; // 黑先
int maxD = 6; // 最大深度

//int getch() // 不回显函数
//{
//    struct termios nts, ots;
//    // 得到当前终端(0表示标准输入)的设置
//    if (tcgetattr(0, &ots) < 0) return EOF;
//    // 设置终端为Raw原始模式，该模式下所有的输入数据以字节为单位被处理
//    nts = ots;
//    cfmakeraw(&nts); 
//    // 设置上更改之后的设置
//    if (tcsetattr(0, TCSANOW, &nts) < 0) return EOF;
//    // 设置还原成老的模式
//    int cr;
//    cr = getchar();
//    if (tcsetattr(0, TCSANOW, &ots) < 0)  return EOF;
//    return cr;
//}

void moveDown() // 向下移动
{   
    rd++;
    for (int i = 6; i >= 1; i--)
    {
        if (num[i][pos] == 0)
        {
            num[i][pos] = color;
            color *= -1;
            return;
        }
    }
}

void moveRight() // 向右移动
{   
    if (pos < 7) pos++;
}

void moveLeft() // 向左移动
{   
    if (pos > 1) pos--;
}

void place(int p, int player) // 放置棋子
{   
    for (int i = 6; i >= 1; i--)
    {
        if (num[i][p] == 0)
        {
            num[i][p] = player;
            return;
        }
    }
}

void remove(int p) // 移走棋子
{   
    for (int i = 1; i <= 6; i++)
    {
        if (num[i][p] != 0)
        {
            num[i][p] = 0;
            return;
        }
    }
}

int findWinner() // 判断游戏是否结束
{
    for (int i = 1; i <= 6; i++)
    {
        for (int j = 1; j <= 7; j++)
        {
            if (num[i][j] == 0) continue;
            // 竖
            if (i + 3 <= 6 && num[i][j] == num[i+1][j] && num[i][j] == num[i+2][j] && num[i][j] == num[i+3][j])
                return num[i][j];
            // 横
            if (j + 3 <= 7 && num[i][j] == num[i][j+1] && num[i][j] == num[i][j+2] && num[i][j] == num[i][j+3])
                return num[i][j];
            // 斜
            if (i + 3 <= 6 && j + 3 <= 7 && num[i][j] == num[i+1][j+1] && num[i][j] == num[i+2][j+2] && num[i][j] == num[i+3][j+3])
                return num[i][j];
            // 斜
            if (i + 3 <= 6 && j - 3 >= 1 && num[i][j] == num[i+1][j-1] && num[i][j] == num[i+2][j-2] && num[i][j] == num[i+3][j-3])
                return num[i][j];
        }
    }
    return 0;
}

bool tie() // 判断平局
{
    for (int j = 1; j <= 7; j++)
    {
        if (num[1][j] == 0) return false;
    }
    return true;
}

void drawBoard() // 打印当前表格
{
	cout << endl << endl;
    cout << "   ";
    for (int i = 1; i <= 7; i++) 
    {
        if (i == pos)
        {
            if (color == BLACK){
            	SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_BLUE);
				cout << "●";
				SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_BLUE);
			}
            else{
            	SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN);
				cout << "○";
				SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_BLUE);
			}
        }
        else cout << "    ";
    }
    cout << "\n";
    // 输出上边框
    cout << "  ╔";
    for (int i = 1; i <= 6; i++) cout << "═══╤";
    cout << "═══╗\n";
    // 输出中间部分
    for (int i = 1; i <= 6; i++) // 行
    {
        cout << "  ║";
        for (int j = 1; j <= 7; j++) // 列
        {
            if (num[i][j] == BLACK)
            {
            	SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_BLUE);
                cout << " ●";
                SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_BLUE);
            } 
            else if (num[i][j] == WHITE)
            {
            	SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN);
                cout << " ○";
                SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_BLUE);
            }
            else cout << "   ";
            if (j != 7)
                cout << "│";
            else
                cout << "║";
        }
        cout << " \n";
        // 输出下边框
        if (i != 6)
        {
            cout << "  ╟";
            for (int i = 1; i <= 6; i++) cout << "───┼";
            cout << "───╢\n";
        }
        else
        {
            cout << "  ╚";
            for (int i = 1; i <= 6; i++) cout << "═══╧";
            cout << "═══╝\n";
        }
    }
}

// 有 两个自由端的3子 +500分
// 有 一个自由端的3子 +100分
// 有 两个自由端的2子 +100分
// 有 一个自由端的2子 +10分

namespace pipi
{
    int eval(int player) // 评估player角色当前的得分
    {
        int value = 0;
        // 横向检测
        for (int i = 1; i <= 6; i++)
        {
            for (int j = 1; j <= 7; j++)
            {
                int cnt = 0, free = 0;
                if (num[i][j] == player)
                {
                    while (num[i][j + cnt] == player)
                    {
                        cnt++;
                    }
                    if (num[i][j-1] == 0) free++; // 左端
                    if (num[i][j+cnt] == 0) free++; // 右端
                    if (cnt == 3 && free == 2) value += 500;
                    if (cnt == 3 && free == 1) value += 100;
                    if (cnt == 2 && free == 2) value += 100;
                    if (cnt == 2 && free == 1) value += 10;
                    j += cnt;
                }
            }
        }
        // cout << value << endl;
        // 纵向检测
        for (int j = 1; j <= 7; j++)
        {
            for (int i = 1; i <= 6; i++)
            {
                int cnt = 0, free = 0;
                if (num[i][j] == player)
                {
                    while (num[i+cnt][j] == player)
                    {
                        cnt++;
                    }
                    if (num[i-1][j] == 0) free++; // 上端
                    if (num[i+cnt][j] == 0) free++; // 下端
                    if (cnt == 3 && free == 2) value += 500;
                    if (cnt == 3 && free == 1) value += 100;
                    if (cnt == 2 && free == 2) value += 100;
                    if (cnt == 2 && free == 1) value += 10;
                    i += cnt;
                }
            }
        }
        // cout << value << endl;
        // 左上右下斜线检测
        for (int i = 1; i <= 6; i++)
        {
            for (int j = 1; j <= 7; j++)
            {
                int cnt = 0, free = 0;
                if (num[i-1][j-1] == player) continue; // 只判断第一个点
                if (num[i][j] == player)
                {
                    while (num[i+cnt][j+cnt] == player)
                    {
                        cnt++;
                    }
                    if (num[i-1][j-1] == 0) free++; // 左上端
                    if (num[i+cnt][j+cnt] == 0) free++; // 右下端
                    if (cnt == 3 && free == 2) value += 500;
                    if (cnt == 3 && free == 1) value += 100;
                    if (cnt == 2 && free == 2) value += 100;
                    if (cnt == 2 && free == 1) value += 10;
                }
            }
        }
        // cout << value << endl;
        // 右上左下斜线检测
        for (int i = 1; i <= 6; i++)
        {
            for (int j = 1; j <= 7; j++)
            {
                int cnt = 0, free = 0;
                if (num[i-1][j+1] == player) continue; // 只判断第一个点
                if (num[i][j] == player)
                {
                    while (num[i+cnt][j-cnt] == player)
                    {
                        cnt++;
                    }
                    if (num[i-1][j+1] == 0) free++; // 右上端
                    if (num[i+cnt][j-cnt] == 0) free++; // 左下端
                    if (cnt == 3 && free == 2) value += 500;
                    if (cnt == 3 && free == 1) value += 100;
                    if (cnt == 2 && free == 2) value += 100;
                    if (cnt == 2 && free == 1) value += 10;
                }
            }
        }
        // cout << value << endl;
        return value;
    }

    int a[55];
    int bestMove = 0;

    int miniMax(int step, int player)
    {
        if (findWinner() == player) // 获胜，评分最大
            return INF;
        if (findWinner() == -1*player) // 失败，评分最小
            return -INF;
        if (step > maxD)
        {
            int ans = eval(player) - eval(-1*player);
            // for (int i = 1; i <= maxD; i++)
            // {
            //     cout << a[i] << " ";
            // }
            // cout << "score: " << ans << endl;
            // drawBoard(); 
            return ans;
        }
        if (step % 2 == 1) // max最大，角色player
        {
            int maxV = -1e9;
            for (int i = 1; i <= 7; i++)
            {
                if (num[1][i] == 0) // 能下i列
                {
                    a[step] = i;
                    place(i, player);
                    int v = miniMax(step + 1, player);
                    if (v > maxV)
                    {
                        maxV = v;
                        if (step == 1) bestMove = i; // 记录选择
                    }
                    remove(i);
                }
            }
            return maxV;
        }
        else // min最小，角色-1*player
        {
            int minV = 1e9;
            for (int i = 1; i <= 7; i++)
            {
                if (num[1][i] == 0) // 能下i列
                {
                    a[step] = i;
                    place(i, -1*player);
                    int v = miniMax(step + 1, player);
                    minV = min(minV, v);
                    remove(i);
                }
            }
            return minV;
        }
    }

    int strategy(int player)
    {
        miniMax(1, player);
        return bestMove;
    }
}



void game() // 开始游戏
{
//    cout << "\033c" << flush;
	system("cls");
    cout << "**********************************" << endl;
    cout << "—————————— Ready Go～ ————————————" << endl;
    cout << "**********************************" << endl;
    getch();

    char ch = 0;
    while (true) // 当游戏没结束时
    {
        while (true) // 玩家回合
        {
            cout << "\033c" << flush;
            drawBoard(); // 打印棋盘
            cout << "Key:" << ch << " Round:" << rd << endl;
            cout << "Tips：" << endl;
            cout << "s —— 下棋" << endl;
            cout << "a —— 左移" << endl;
            cout << "d —— 右移" << endl;
            cout << "Esc —— 退出游戏" << endl;
            cout << "n —— 开始新游戏" << endl;
            cout << "选择以上指令！" << endl;
            
            ch = getch(); // 输入操作指令
            if (ch == 's') 
            {
                moveDown(); //下键
                break;
            }
            else if (ch == 'a') moveLeft(); //左键
            else if (ch == 'd') moveRight(); //右键
            else if (ch == 27) exit(0);
            else if (ch == 'n') // 开始新游戏
            {
                rd = 0; // 清空操作次数
                memset(num, 0, sizeof(num)); // 清空表格数据
                return; 
            }
            else
            {
                cout << endl << "———————输入有误，请重新输入指令！———————" << endl << endl;
                continue;
            }
        }
        cout << "\033c" << flush;
        drawBoard(); // 打印棋盘
        int winner = findWinner();
        if (winner != 0)
        {
            if (winner == BLACK)
            {
                cout << " ● ";
            } 
            else if (winner == WHITE)
            {
                cout << " ○ ";
            }
            cout << "获胜" << endl;
            break;
        }
        if (tie()) // 判断平局
        {
            cout << "平局" << endl;
            break;
        }

        // 电脑
        pos = pipi::strategy(WHITE);
        moveDown();
        cout << "\033c" << flush;
        drawBoard(); // 打印棋盘
        winner = findWinner();
        if (winner != 0)
        {
            if (winner == BLACK)
            {
            	SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_BLUE);
                cout << " ● ";
                SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_BLUE);
            } 
            else if (winner == WHITE)
            {
            	SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN);
                cout << " ○ ";
                SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), FOREGROUND_INTENSITY | FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_BLUE);
            }
            cout << "获胜" << endl;
            break;
        }
        if (tie()) // 判断平局
        {
            cout << "平局" << endl;
            break;
        }
    }
}

void intro() // 游戏规则展示
{
    cout << "***********************************************************" << endl;
    cout << "欢迎来到 四子棋 游戏～" << endl;
    cout << "在这个游戏里会有一个 6*7 的表格" << endl;
    cout << "可以选择 a←、s↓、d→，选择某一列" << endl;
    cout << "当 上下或斜线上四子连成一条直线 游戏结束！" << endl; 
    cout << "点击【ENTER】开始游戏" << endl;
    cout << "点击【ESC】退出游戏" << endl;
    cout << "***********************************************************" << endl;
}

void init()
{
	srand(time(0));
	memset(num, 999999, sizeof(num));
    for (int i = 1; i <= 6; i++)
        for (int j = 1; j <= 7; j++)
            num[i][j] = 0;
	rd = 0; // 回合数
	pos = 1; // 所在列
	color = BLACK; // 黑先
}

int main()
{
    while (true)
    {
    	init(); // 初始化
        intro(); // 游戏规则展示
        char ch;
        ch = getch(); // 不回显函数，当用户按下某个字符时，函数自动读取，无需按回车
        if (ch == 13) // CR回车的ascii是13
        {
            game(); // 开始游戏
        }
        else if (ch == 27) // ESC的ascii是27
        {
            cout << "退出游戏！" << endl;
            break;
        }
        else  cout << "输入有误，请再次输入！" << endl;
    }
    return 0;
}