五子棋 AI篇

var chess=document.getElementById("chess");
var cxt=chess.getContext(‘2d‘);

cxt.strokeStyle="#BFBFBF";
var bgimg=new Image();
bgimg.src="img/1.jpg";
bgimg.onload=function(){
     cxt.drawImage(bgimg,0,0,450,450);//画背景
    drawline();//画棋盘线
    drawText();
}

var drawline=function(){
    for(var i=0;i<15;i++)
    {
        cxt.moveTo(15+i*30,15);
        cxt.lineTo(15+i*30,435);
        cxt.stroke();
        cxt.moveTo(15,15+i*30);
        cxt.lineTo(435,15+i*30);
        cxt.stroke();
    }
}

var drawText=function(){
    cxt.fillStyle="#333";
    cxt.textAlign="right";
    for(var i=0;i<15;i++)
    {

        cxt.fillText((i+1).toString(),18+i*30,12);
        cxt.fillText((i+1).toString(),12,20+i*30);
    }
    
}

var oneStep=function(i,j,me){//画棋子
    cxt.beginPath();
    cxt.arc(15+i*30,15+j*30,13,0,2*Math.PI);
    cxt.closePath();
    var gradient=cxt.createRadialGradient(15+i*30+2,15+j*30-2,13,15+i*30+2,15+j*30-2,0);//渐变
    if(me){
        gradient.addColorStop(0,"#0a0a0a");
        gradient.addColorStop(1,"#636766");
    }else{
        gradient.addColorStop(0,"#D1D1D1");
        gradient.addColorStop(1,"#F9F9F9");
    }

    cxt.fillStyle=gradient;
    cxt.fill();
}

//赢法数组
var wins = [];
//第count种赢法
var count = 0;

//赢法的统计数组
var myWin = [];
var computerWin = [];

//结束标识
var gameover = false;
var chess = document.getElementById("chess");

var me = true; //判断是黑棋还是白棋
var chessBoard = []; //判断是否已落子
for(var i = 0; i < 15; i++) {
    chessBoard[i] = [];
    for(var j = 0; j < 15; j++) {
        chessBoard[i][j] = 0;
    }
}
//再来一次
var again=document.getElementById("again");
again.onclick=function(){
    window.location.reload();
}

//初始化数据
for(var i = 0; i < 15; i++) {
    wins[i] = [];
    for(var j = 0; j < 15; j++) {
        wins[i][j] = [];
    }
}

//横线赢法
for(var i = 0; i < 15; i++) {
    for(var j = 0; j < 11; j++) {
        for(var k = 0; k < 5; k++) {
            wins[i][j + k][count] = true;
        }
        count++;
    }
}
//竖线赢法
for(var i = 0; i < 15; i++) {
    for(var j = 0; j < 11; j++) {
        for(var k = 0; k < 5; k++) {
            wins[j + k][i][count] = true;
        }
        count++;
    }
}
//斜线赢法
for(var i = 0; i < 11; i++) {
    for(var j = 0; j < 11; j++) {
        for(var k = 0; k < 5; k++) {
            wins[i + k][j + k][count] = true;
        }
        count++;
    }
}
//反斜线赢法
for(var i = 0; i < 11; i++) {
    for(var j = 14; j > 3; j--) {
        for(var k = 0; k < 5; k++) {
            wins[i + k][j - k][count] = true;
        }
        count++;
    }
}
//console.log(count); //572

//初始化
for(var i = 0; i < count; i++) {
    myWin[i] = 0;
    computerWin[i] = 0;
}

chess.onclick = function(e) { //点击棋盘下棋
    if(gameover) {
        return;
    }
    if(!me) {
        return;
    }
    var x = e.offsetX;
    var y = e.offsetY;
    var i = Math.floor(x / 30);
    var j = Math.floor(y / 30);
    if(chessBoard[i][j] == 0) {
        oneStep(i, j, me);
        chessBoard[i][j] = 1;
        for(var k = 0; k < count; k++) {
            if(wins[i][j][k]) {
                myWin[k]++;
                computerWin[k] = 6;
                if(myWin[k] == 5) {
                    gameover = true;
                    alert("恭喜，你赢了");
                }
            }
        }
        if(!gameover) {
            computerAI();
        }
    }
}
var computerAI = function() {
    var myScore = [];
    var computerScore = [];
    var max = 0;
    var u = 0,
        v = 0;
    //初始化
    for(var i = 0; i < 15; i++) {
        myScore[i] = [];
        computerScore[i] = [];
        for(var j = 0; j < 15; j++) {
            myScore[i][j] = 0;
            computerScore[i][j] = 0;
        }
    }

    for(var i = 0; i < 15; i++) {
        for(var j = 0; j < 15; j++) {
            if(chessBoard[i][j] == 0) { //此处未落子
                for(var k = 0; k < count; k++) {
                    if(wins[i][j][k]) { //某一种赢法存在
                        switch(myWin[k]) {
                            case 1:
                                myScore[i][j] += 200;
                                break;
                            case 2:
                                myScore[i][j] += 400;
                                break;
                            case 3:
                                myScore[i][j] += 2000;
                                break;
                            case 4:
                                myScore[i][j] += 10000;
                                break;
                        }
                        switch(computerWin[k]) {
                            case 1:
                                computerScore[i][j] += 220;
                                break;
                            case 2:
                                computerScore[i][j] += 420;
                                break;
                            case 3:
                                computerScore[i][j] += 2100;
                                break;
                            case 4:
                                computerScore[i][j] += 20000;
                                break;
                        }
                    }

                }
                if(myScore[i][j] > max) {
                    max = myScore[i][j];
                    u = i;
                    v = j;
                } else if(myScore[i][j] == max) {
                    if(computerScore[i][j] > computerScore[u][v]) {
                        u = i;
                        v = j;
                    }
                }
                if(computerScore[i][j] > max) {
                    max = computerScore[i][j];
                    u = i;
                    v = j;
                } else if(computerScore[i][j] == max) {
                    if(myScore[i][j] > myScore[u][v]) {
                        u = i;
                        v = j;
                    }
                }
            }
        }
    }

    setTimeout(function(){
        me = !me;
        oneStep(u, v, false);
    },600);
    
    chessBoard[u][v] = 2; //计算机落子
    for(var k = 0; k < count; k++) {
        if(wins[u][v][k]) {
            computerWin[k]++;
            myWin[k] = 6;
            if(computerWin[k] == 5) {
                gameover = true;
                alert("很遗憾，你输了");
            }
        }
    }
    if(!gameover) {
        me = !me;
    }
}