图论——Dijkstra算法matlab代码

Dijkstra算法步骤
（1）构造邻接矩阵
（2）定义起始点
（3）运行代码

M=[  0     5     9   Inf   Inf   Inf   InfInf     0   Inf   Inf    12   Inf   InfInf     3     0    15   Inf    23   InfInf     6   Inf     0   Inf     8     7Inf    12   Inf     5     0   Inf    14Inf   Inf   Inf   Inf   Inf     0    10Inf   Inf   Inf   Inf   Inf   Inf     0];
first=2;
last=4;
[m,n]=size(M);
L=zeros(1,m);
symbol=zeros(1,m);
direction=zeros(1,m);
for i=1:mif(i~=first)L(i)=inf;enddirection(i)=first;
end
judge=1;
while judge
for i=1:mif(symbol(i)==0)min=L(i);temporary=i;breakend
end
for i=1:mif(symbol(i)==0)if(L(i)<min)min=L(i);temporary=i;endend
end
k=temporary;
for j=1:mif(symbol(1,j)==0)if(M(k,j)==inf)continue;elseif(L(k)+M(k,j)<L(j))L(j)=L(k)+M(k,j);direction(j)=k;endendend
end
symbol(k)=1;
num=0;
for i=1:mif(symbol(i)==1)num=num+1;end
end
if(num==m)judge=0;
end
end
p=last;
arrow=zeros(1,m);
arrow(1)=last;
i=2;
while p~=firstarrow(1,i)=direction(p);i=i+1;p=direction(p);
end
distance=L(last);