商人过河问题——MATLAB实现

本文使用MATLAB实现了商人过河为题，以下为部分代码：

boat_p函数：

function boat=boat_p(pm,tybe)
boat=[];
switch tybe
    case 1
        for i=pm:-1:2
            for j=0:i-1
                boat_pass=[j,i-j-1];
                boat=[boat;boat_pass];
            end
        end
    case 2
        for i=2:pm
            for j=0:i-1
                boat_pass=[j,i-j-1];
                boat=[boat;boat_pass];
            end
        end
end
end

history函数：

function qa_h=history(qa,tybe)
n=length(qa);
switch tybe
    case 0
        qa_h=[];
        i=3;
        while i<=n
            qa_h=[qa_h;qa(i,:)];
            i=i+2;
        end
    case 1
         qa_h=[];
        i=2;
        while i<=n
            qa_h=[qa_h;qa(i,:)];
            i=i+2;
        end
end

member函数：

function y=member(a,b)
h=size(a);
count=0;
for i=1:h(1)
    if isequal(b,a(i,:))
        count=count+1;
    end
end
if count==0  
    y=0;
else
    y=1;    
end
end

safe_situation函数：

function safe=safe_situation(pm)
safe=[];
for i=0:pm
    safe_pass=[0,i;pm,i;i,i];
    safe=[safe;safe_pass];
end
end

pass_river函数：

clear;
pm=4;    %商人和仆人对数，假设一个商人带一个仆人
%由于绘图限制，请不要超过11
qa=[pm,pm];
n=1;   
safe=safe_situation(pm);
boat1=boat_p(pm,1);   
boat2=boat_p(pm,2);    
n1=length(boat1);n2=length(boat2);
draw(pm,qa,n);pause(3);
qa_pass=qa(n,:);
qa_pass=qa_pass-boat1(1,:);
qa(n+1,:)=qa_pass;
n=n+1;
qa_h=history(qa,mod(n,2));
draw(pm,qa,n);pause(3);
while sum(qa(n,:))~=0   
    if mod(n,2)==1
        for i=1:n1
            qa_pass=qa(n,:);
            qa_pass=qa_pass-boat1(i,:);
            if member(safe,qa_pass)==1&&member(qa_h,qa_pass)==0
                qa(n+1,:)=qa_pass;
                break;
            end
        end
    end
    if mod(n,2)==0
        for i=1:n2
            qa_pass=qa(n,:);
            qa_pass=qa_pass+boat2(i,:);
            if member(safe,qa_pass)==1&&member(qa_h,qa_pass)==0
                qa(n+1,:)=qa_pass;
                break;
            end
        end
    end
    n=n+1;
    qa_h=history(qa,mod(n,2));  
    draw(pm,qa,n);
    pause(3);
end

代码运行效果演示：