井字遊戲(with MiniMax)

#include <conio.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <time.h>
#include <windows.h>
using namespace std;
char k;
int p=0;
vector<string> map(9, "");
string chess;

bool IsMoveLeft(){ //判定還有沒有格子可以下
    for(int i = 0 ; i < 9 ; i++){
        if( map[i] == "" ){
            return true;
        }
    }
    return false;
}

//ＸＯ
int evalboard(){ //算分
    for( int i = 0 ; i <=6 ; i+=3 ){
        if( map[i] != "" && map[i] == map[i+1] && map[i] == map[i+2] ){
            if( map[i] == "Ｏ"){
                return 10;
            }
            else{
                return -10;
            }
        }
    }
    for( int i = 0 ; i <=2 ; i++ ){
        if( map[i] != "" && map[i] == map[i+3] && map[i] == map[i+6] ){
            if( map[i] == "Ｏ"){
                return 10;
            }
            else{
                return -10;
            }
        }
    }
    if( map[0] != "" && map[0] == map[4] && map[0] == map[8] ){
        if( map[0] == "Ｏ"){
                return 10;
            }
            else{
                return -10;
            }
    }
    if( map[2] != "" && map[2] == map[4] && map[2] == map[6] ){
        if( map[2] == "Ｏ"){
                return 10;
            }
            else{
                return -10;
            }
    }
    return 0;
}

void draw() {
    system("cls");  //cls means clear screen
    cout << IsMoveLeft() <<endl;
    cout << evalboard() <<endl;
    for( int i = 0 ; i <9 ; i++ ){
        if(map[i] != ""){
            cout << map[i];
        }
        else if(i ==p){
            cout << "□";
        }
        else{
            cout << "■";
        }
        if( i % 3 == 2 ){
            cout << endl;
        }
    }
}

int minimax( int depth , bool ismax ){ //MiniMax決策樹
    int score = evalboard();
    if( score != 0 ){
        return score;
    }
    if( IsMoveLeft() == false ){
        return 0;
    }
    int best , a;
    if(ismax){
        best = -11;
        for(int i = 0 ; i < 9 ; i++){
            if(map[i] == ""){
                map[i] = "Ｏ";
                a = minimax(depth+1 , not ismax) - depth;
                if( a > best ){
                    best = a;
                }
                map[i] = "";
            }
        }
    }
    else{
        best = 11;
        for(int i = 0 ; i < 9 ; i++){
            if( map[i] == "" ){
                map[i] = "Ｘ";
                a = minimax(depth+1 , not ismax ) + depth;
                if( a < best ){
                    best = a;
                }
                map[i] = "";
            }
        }
    }
    return best;
}

void BestMove(){
    if( IsMoveLeft() == false ){
        draw();
        cout << "tie\n";
    }
    else{
        int bestval = -11;
        int bestidx = -1;
        for(int i = 0 ; i < 9 ; i++){
            if(map[i] == ""){
                map[i] = "Ｏ";
                int moveval = minimax(0 , false);
                map[i] = "";
                if( moveval > bestval ){
                    bestval = moveval;
                    bestidx = i;
                }
            }
        }
        if( bestidx > -1 ){
            map[bestidx] = "Ｏ";
        }
    }
}

int main() {

    chess="Ｘ";  //ＸＯ全形字元，不然棋盤會歪掉，shift+space可以切換全形半形
    draw();
    string whowin="";
    while (1) {
        if (kbhit()) {
            k=_getch();
            if( k == 'q' ){
                break;
            }
            else if( k == 'e' ){
                p = p-3;
            }
            else if( k == 'd' ){
                p = p+3;
            }
            else if( k == 's' ){
                p = p-1;
            }
            else if( k == 'f' ){
                p = p+1;
            }
            else if( k == 'c' ){
                if( map[p] == "" ){
                    map[p] = chess;
                    if( chess == "Ｘ" ){
                        BestMove();
                        //chess = "Ｏ";
                    }
                    else{
                        chess = "Ｘ";
                    }
                }
            }

            for( int i = 0 ; i <=6 ; i+=3 ){
                if( map[i] != "" && map[i] == map[i+1] && map[i] == map[i+2] ){
                    whowin = map[i];
                }
            }
            for( int i = 0 ; i <=2 ; i++ ){
                if( map[i] != "" && map[i] == map[i+3] && map[i] == map[i+6] ){
                    whowin = map[i];
                }
            }
            if( map[0] != "" && map[0] == map[4] && map[0] == map[8] ){
                whowin = map[0];
            }
            if( map[2] != "" && map[2] == map[4] && map[2] == map[6] ){
                whowin = map[2];
            }


            draw();
            if( whowin != "" ){
                cout << whowin << "win";
                break;
            }
        }

    }

    return 0;
}