猴子摘香蕉问题-人工智能模拟

题目：
利用一阶谓词逻辑求解猴子摘香蕉问题：房内有一个猴子，一个箱子，天花板上挂了一串香蕉，其位置如图1所示，猴子为了拿到香蕉，它必须把箱子搬到香蕉下面，然后再爬到箱子上。请定义必要的谓词，列出问题的初始化状态（即下图所示状态），目标状态（猴子拿到了香蕉，站在箱子上，箱子位于位置b）。（附加：从初始状态到目标状态的谓词演算过程。）

1.定义描述环境状态的谓词。
AT(x,w)：x在w处，个体域：x?{monkey}，w?{a,b,c,box}；
HOLD(x,t)：x手中拿着t，个体域：t?{box,banana}；
EMPTY(x)：x手中是空的；
ON(t,y)：t在y处，个体域：y?{b,c,ceiling}；
CLEAR(y)：y上是空的；
BOX(u)：u是箱子，个体域：u?{box}；
BANANA(v)：v是香蕉，个体域：v?{banana}；

2.使用谓词、连结词、量词来表示环境状态。
问题的初始状态可表示为：So：AT(monkey,a)?EMPTY(monkey)?ON(box,c)?ON(banana,ceiling)?CLEAR(b)?BOX(box)?
BANANA(banana)
要达到的目标状态为：Sg：
AT(monkey,box)?HOLD(monkey,banana)?ON(box,b)?CLEAR(ceiling)?CLEAR©?
BOX(box)?BANANA(banana)

3.从初始状态到目标状态的转化, 猴子需要完成一系列操作, 定义操作类谓词表示其动作。
WALK(m,n)：猴子从m走到n处，个体域：m,n?{a,b,c}；
CARRY(s,r)：猴子在r处拿到s，个体域：r?{c,ceiling}，s?{box,banana}；
CLIMB(u,b)：猴子在b处爬上u；
这3个操作也可分别用条件和动作来表示。条件直接用谓词公式表示，是为完成相应操作所必须具备的条件；当条件中的事实使其均为真时，则可激活操作规则，于是可执行该规则中的动作部分。动作通过前后状态的变化表示，即通过从动作前删除或增加谓词公式来描述动作后的状态。

WALK(m,n)：猴子从m走到n处
条件：AT(monkey,m)
动作：

CARRY(s,r)：猴子在r处拿到s
条件：AT(monkey,r)?EMPTY(monkey)?ON(s,r)?BOX(box)?BANANA(banana)
动作：

CLIMB(u,b)：猴子在b处爬上u
条件：AT(monkey,b)?HOLD(monkey,u)?CLEAR(b)?BOX(box)?BANANA(banana)
动作：

4.按照行动计划, 一步步进行状态替换, 直至目标状态
AT(monkey,a)?EMPTY(monkey)?ON(box,c)?ON(banana,ceiling)?CLEAR(b)?BOX(box)?
BANANA(banana)
AT(monkey,c)?EMPTY(monkey)?ON(box,c)?ON(banana,ceiling)?CLEAR(b)?BOX(box)?
BANANA(banana)
AT(monkey,c)?HOLD(monkey,box)?ON(banana,ceiling)?CLEAR(b)?CLEAR©?BOX(box)?
BANANA(banana)
AT(monkey,b)?HOLD(monkey,box)?ON(banana,ceiling)?CLEAR(b)?CLEAR©?BOX(box)?
BANANA(banana)
AT(monkey,box)?EMPTY(monkey)?ON(box,b)?ON(banana,ceiling)?CLEAR©?BOX(box)?
BANANA(banana)
AT(monkey,box)?HOLD(monkey,banana)?ON(box,b)?CLEAR(ceiling)?CLEAR©?BOX(box)?
BANANA(banana)（目标得解）
猴子行动的规则序列是：WALK(a,c)→CARRY(c,box)→WALK(c,b)→CLIMB(box,b)→
CARRY(banana,ceiling)

代码：

#include 
#include
using namespace std;

struct State
{
	int monkey; /*-1:Monkey at A;0: Monkey at B;1:Monkey at C;*/
	int box; /*-1:box at A;0:box at B;1:box at C;*/
	int banana; /*Banana at B,Banana=0*/
	int monbox; /*-1: monkey on the box;1: monkey  the box;*/
};
struct State States[150];
string routesave[150];
/*function monkeygoto,it makes the monkey goto the other place*/
void monkeygoto(int b, int i)
{
	
	int a;
	a = b;
	if (a == -1)
	{
		routesave[i] = "Monkey go to A";
		States[i + 1] = States[i];
		States[i + 1].monkey = -1;
	}
	else if (a == 0)
	{
		routesave[i] = "Monkey go to B";
		States[i + 1] = States[i];
		States[i + 1].monkey = 0;
	}
	else if (a == 1)
	{
		routesave[i] = "Monkey go to C";
		States[i + 1] = States[i];
		States[i + 1].monkey = 1;
	}
	else
	{
		printf("parameter is wrong");
	}
}
/*end function monkeyygoto*/
/*function movebox,the monkey move the box to the other place*/
void movebox(int a, int i)
{
	
	int B;
	B = a;
	if (B == -1)
	{
		routesave[i] = "monkey move box to A";
		States[i + 1] = States[i];
		States[i + 1].monkey = -1;
		States[i + 1].box = -1;
	}
	else if (B == 0)
	{
		routesave[i] = "monkey move box to B";
		States[i + 1] = States[i];
		States[i + 1].monkey = 0;
		States[i + 1].box = 0;
	}
	else if (B == 1)
	{
		routesave[i] = "monkey move box to C";
		States[i + 1] = States[i];
		States[i + 1].monkey = 1;
		States[i + 1].box = 1;
	}
	else
	{
		printf("parameter is wrong");
	}
}
/*end function movebox*/
/*function climbonto,the monkey climb onto the box*/
void climbonto(int i)
{
	
	routesave[i] = "Monkey climb onto the box";
	States[i + 1] = States[i];
	States[i + 1].monbox = 1;
}
/*function climbdown,monkey climb down from the box*/
void climbdown(int i)
{
	
	routesave[i] = "Monkey climb down from the box";
	States[i + 1] = States[i];
	States[i + 1].monbox = -1;
}
/*function reach,if the monkey,box,and banana are at the same place,the monkey reach banana*/
void reach(int i)
{
	routesave[i] = "Monkey reach the banana";
}
/*output the solution to the problem*/
void showSolution(int i)
{
	int c;
	cout<<"Result to problem:"<<endl;
	for (c = 0; c < i + 1; c++)
	{
		cout<<"Step"<< c + 1<<":" <<routesave[c]<<endl;
	}
	cout<<endl;
}
/*perform next step*/
void nextStep(int i)
{
	int c;
	int j;
	if (i >= 150)
	{
		cout << "steplength reached 150,have problem " << endl;
		return;
	}
	for (c = 0; c < i; c++) /*if the current state is same to previous,retrospect*/
	{
		if (States[c].monkey == States[i].monkey&&States[c].box == States[i].box&&States[c].banana == States[i].banana&&States[c].monbox == States[i].monbox)
		{
			return;
		}
	}
	if (States[i].monbox == 1 && States[i].monkey == States[0].banana && States[i].banana == States[0].banana && States[i].box == States[0].banana)
	{
		showSolution(i);
		cout << "Press any key to continue " << endl;
		//getchar();/*to save screen for user,press any key to continue*/
		return;
	}
	j = i + 1;
	if (States[i].box == States[i].monkey&&States[i].box == States[i].banana)
	{
		if (States[i].monbox == -1)
		{
			climbonto(i);
			reach(i + 1);
			nextStep(j);
			
		}
		else
		{
			reach(i + 1);
			nextStep(j);
			
		}
	}
	else if (States[i].box == States[i].monkey&&States[i].box != States[i].banana)
	{
		if (States[i].monbox == -1)
		{
			
			movebox(States[i].banana, i);
			nextStep(j);
			
		}
		else
		{
			climbdown(i);
			nextStep(j);
			
		}
	}
	else if (States[i].box != States[i].monkey&&States[i].box == States[i].banana)
	{
		monkeygoto(States[i].box, i);
		nextStep(j);
		
	}
	else if (States[i].box != States[i].monkey&&States[i].box != States[i].banana)
	{
		monkeygoto(States[i].box, i);
		nextStep(j);
		
	}
}
int main()
{
	cout << "初始位置：" << endl;
	cout << "monkey(-1 or 0 or 1):";
	cin>>States[0].monkey;
	cout << "box(-1 or 0 or 1):";
	cin >> States[0].box;
	cout << "banana(-1 or 0 or 1):";
	cin>>States[0].banana;
	cout << "monbox(-1 or 1):";
	cin>>States[0].monbox;
	nextStep(0);
}