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 Inf
Inf 0 Inf Inf 12 Inf Inf
Inf 3 0 15 Inf 23 Inf
Inf 6 Inf 0 Inf 8 7
Inf 12 Inf 5 0 Inf 14
Inf Inf Inf Inf Inf 0 10
Inf 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:m
if(i~=first)
L(i)=inf;
end
direction(i)=first;
end
judge=1;
while judge
for i=1:m
if(symbol(i)==0)
min=L(i);
temporary=i;
break
end
end
for i=1:m
if(symbol(i)==0)
if(L(i)<min)
min=L(i);
temporary=i;
end
end
end
k=temporary;
for j=1:m
if(symbol(1,j)==0)
if(M(k,j)==inf)
continue;
else
if(L(k)+M(k,j)<L(j))
L(j)=L(k)+M(k,j);
direction(j)=k;
end
end
end
end
symbol(k)=1;
num=0;
for i=1:m
if(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~=first
arrow(1,i)=direction(p);
i=i+1;
p=direction(p);
end
distance=L(last);floyd 算法代码
d=[inf 6 0 4 0 0 0
0 inf 0 0 5 0 0
4 7 inf 0 0 5 0
0 0 4 inf 0 3 0
0 0 2 0 inf 0 0
0 0 0 0 4 inf 5
0 0 0 0 6 0 inf];
[m,n]=size(d);
first=1;
last=7;
direction=zeros(m,m);
for i=1:m
direction(:,i)=i;
end
for i=1:m
for j=1:m
for k=1:m
small=min(d(i,k),d(k,j));
if d(i,j)<small
d(i,j)=small;
direction(i,j)=direction(i,k);
end
end
end
end
arrow=zeros(1,m);
arrow(1)=first;
i=2;
p=first;
while p~=last
p=direction(p,last);
arrow(i)=p;
i=i+1;
end
生成树算法代码
M=[ 0 17 11 inf inf inf
17 0 13 12 28 15
11 13 0 inf 19 inf
inf 12 inf 0 inf 16
inf 28 19 inf 0 10
inf 15 inf 16 10 0];
[m,n]=size(M);
X=zeros(m,n);
Y=zeros(m);
Z=zeros(m);
Y(1)=1;
for i=2:m
Z(i)=i;
end
judge=1;
while judge
for i=1:m
if(Y(i)~=0)
for j=1:m
if(Z(j)~=0)
min=M(i,j);
a=i;
b=j;
end
end
end
end
for i=1:m
if(Y(i)~=0)
for j=1:m
if(Z(j)~=0)
if(M(i,j)<min)
min=M(i,j);
a=i;
b=j;
end
end
end
end
end
Y(b)=b;
Z(b)=0;
X(a,b)=1;
X(b,a)=1;
c=0;
for i=1:m
if(Y(i)~=0)
c=c+1;
end
end
if(c==m)
judge=0;
end
end
