1，简介

Qt开发的AI人机对战五子棋游戏。

2，效果

3，思路

棋盘为15*15矩阵

棋子Item 存1个坐标点、一个颜色类型(黑棋还是白棋)

绘制顺序依次为 棋盘、棋子、鼠标（也是一个棋子）

核心算法（判断五子连）：

对所下的棋子，向 8个方向分别统计相邻的同色棋子个数

8个方向为：左、左上、上、右上、右、右下、下、左下

然后在一条直线的2个方向的棋子个数加起来，即得到该直线上与所下棋子相邻的同色棋子个数

棋子类Item.h：

包含一个QPoint圆心坐标，和一个bool变量，代表是黑方还是白方

#pragma once
#include <QPoint>
 
class Item
{
public:
	Item(void);
	Item(QPoint pt,bool bBlack);
	~Item(void);
 
    //重载"=="操作符，判等需要颜色和位置都相同
	bool operator==(const Item &t1)const
	{
        return ((mPt == t1.mPt) && (mBlack == t1.mBlack));
	}  
 
    QPoint mPt;
    bool mBlack;
private:
 
 
};
 
 

MainWindow.h：

QVector<Item> mItems 保存所有棋子。

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
#include "Item.h"
#include "qmap.h"
 
namespace Ui {
class MainWindow;
}
 
 
#define CHESS_ROWS		15
#define CHESS_COLUMES	15
#define RECT_WIDTH		50
#define RECT_HEIGHT		50
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
protected:
    void paintEvent(QPaintEvent *);
	void mousePressEvent(QMouseEvent *);
 
private:
	void DrawChessboard();
	void DrawItems();
	void DrawItemWithMouse();
 
	void DrawChessAtPoint(QPainter& painter,QPoint& pt);
    
    //统计某个方向(共8个方向)上的相连个数，用QPoint表示统计方向，如(1,1)表示右下方,（-1,0）表示向左
	int CountNearItem(Item item,QPoint ptDirection);	
 
private:
    Ui::MainWindow *ui;
 
    QVector<Item> mItems;
    bool mIsBlackTurn;	//当前该黑棋下
};
 
#endif // MAINWINDOW_H

MainWindow.cpp:

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "qpainter.h"
#include "qevent.h"
#include "qpoint.h"
#include "qmessagebox.h"
 
 
 
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
	ui->mainToolBar->hide();
	ui->menuBar->hide();
 
	resize((CHESS_COLUMES + 1)*RECT_WIDTH  ,(CHESS_ROWS + 1)*RECT_HEIGHT);
 
	mIsBlackTurn = true;
 
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::paintEvent(QPaintEvent *e)
{
	DrawChessboard();		//画棋盘
	DrawItems();			//画棋子
	DrawItemWithMouse();	//画鼠标（当前方的棋子形状）
 
	update();
}
 
void MainWindow::DrawChessboard()
{
	QPainter painter(this);
	painter.setRenderHint(QPainter::HighQualityAntialiasing, true); 
	painter.setBrush(Qt::darkYellow);
	painter.setPen(QPen(QColor(Qt::black),2));
 
	for(int i = 0;i<CHESS_COLUMES; i++)
	{
		for (int j = 0; j<CHESS_ROWS; j++)
		{
			painter.drawRect( (i+0.5)*RECT_WIDTH,(j+0.5)*RECT_HEIGHT,RECT_WIDTH,RECT_HEIGHT);
		}
	}
}
 
void MainWindow::DrawItems()
{
	QPainter painter(this);
	painter.setPen(QPen(QColor(Qt::transparent)));
 
	for (int i = 0; i<mItems.size(); i++)
	{
		Item item = mItems[i];
		if (item.mBlack)
		{
			painter.setBrush(Qt::black);
		}
		else
		{
			painter.setBrush(Qt::white);
		}
		DrawChessAtPoint(painter,item.mPt);
	}
}
 
void MainWindow::DrawChessAtPoint(QPainter& painter,QPoint& pt)
{
	//painter.drawRect( (pt.x()+0.5)*RECT_WIDTH,(pt.y()+0.5)*RECT_HEIGHT,RECT_WIDTH,RECT_HEIGHT);
 
	QPoint ptCenter((pt.x()+0.5)*RECT_WIDTH,(pt.y()+0.5)*RECT_HEIGHT);
	painter.drawEllipse(ptCenter,RECT_WIDTH / 2,RECT_HEIGHT / 2);
}
 
void MainWindow::DrawItemWithMouse()
{
	QPainter painter(this);
	painter.setPen(QPen(QColor(Qt::transparent)));
 
	if (mIsBlackTurn)
	{
		painter.setBrush(Qt::black);
	}
	else
	{
		painter.setBrush(Qt::white);
	}
	//QPoint pt;
	//pt.setX( (QCursor::pos().x() ) / RECT_WIDTH);
	//pt.setY( (QCursor::pos().y() ) / RECT_HEIGHT);
 
	//DrawChessAtPoint(painter,pt);
 
	painter.drawEllipse(mapFromGlobal(QCursor::pos()),RECT_WIDTH / 2,RECT_HEIGHT / 2);
	
}
 
void MainWindow::mousePressEvent(QMouseEvent * e)
{
	//求鼠标点击处的棋子点pt
	QPoint pt;
	pt.setX( (e->pos().x() ) / RECT_WIDTH);
	pt.setY( (e->pos().y() ) / RECT_HEIGHT);
 
	//如果已存在棋子，就什么也不做
	for (int i = 0; i<mItems.size(); i++)
	{
		Item item = mItems[i];
		if (item.mPt == pt)
		{
			//已有棋子
			return;
		}
	}
	//不存在棋子，就下一个
	Item item(pt,mIsBlackTurn);
	mItems.append(item);
 
	//统计4个方向是否五子连
	int nLeft =			CountNearItem(item,QPoint(-1,0));
	int nLeftUp =		CountNearItem(item,QPoint(-1,-1));
	int nUp =			CountNearItem(item,QPoint(0,-1));
	int nRightUp =		CountNearItem(item,QPoint(1,-1));
	int nRight =		CountNearItem(item,QPoint(1,0));
	int nRightDown =	CountNearItem(item,QPoint(1,1));
	int nDown =			CountNearItem(item,QPoint(0,1));
	int nLeftDown =		CountNearItem(item,QPoint(-1,1));
	if ( (nLeft + nRight) >= 4 ||
		 (nLeftUp + nRightDown) >= 4 ||
		 (nUp + nDown) >= 4 ||
		 (nRightUp + nLeftDown) >= 4 )
	{
		QString str = mIsBlackTurn?"Black":"White";
		QMessageBox::information(NULL,  "GAME OVER",str, QMessageBox::Yes , QMessageBox::Yes);
		mItems.clear();
		//NewGame();
		return;
	}
	//该另一方下棋了
	mIsBlackTurn = !mIsBlackTurn;
}
 
int MainWindow::CountNearItem(Item item,QPoint ptDirection)
{
	int nCount = 0;
	item.mPt += ptDirection;
 
	while (mItems.contains(item))
	{
		nCount++;
		item.mPt += ptDirection;
	}
	return nCount;
}
 
 

判断五子连的算法：

（统计某个棋子item在某个方向ptDirection上，相邻的同色棋子数目）

方向用QPoint来表示，是取8个方向上1个单位坐标的点，例如：向上（0,1）、向右上（1,1）、向右（1,0）等

int MainWindow::CountNearItem(Item item,QPoint ptDirection)
{
	int nCount = 0;
	item.mPt += ptDirection;
 
	while (mItems.contains(item))
	{
		nCount++;
		item.mPt += ptDirection;
	}
	return nCount;
}

这样在每次下棋后，判断所下棋子横、竖、正斜、反斜4大方向上，每个方向相邻同色棋子数目，达到5个即胜利。

这里的4个方向，每个方向需要调用CountNearItem函数两次，比如横向，需要分别以向右（1,0）和向左（-1,0）来调

CountNearItem函数。