function [T c]=Primf(a)
% 求最小生成树的Prim算法
% function [T c]=Primf(a)
% a：边权矩阵。
% c:生成树的费用;
% T:生成树的边集合;
l=length(a);
a(a==0)=inf;
k=1:l;
listV(k)=0;
listV(1)=1;
e=1;
while (e<l)
min=inf;
for i=1:l
if listV(i)==1
for j=1:l
if listV(j)==0 & min>a(i,j)
min=a(i,j);b=a(i,j);
s=i;d=j;
end
end
end
end
listV(d)=1;
distance(e)=b;
source(e)=s;
destination(e)=d;
e=e+1;
end
T=[source;destination];
for g=1:e-1
c(g)=a(T(1,g),T(2,g));
end
c;
%=====================otherway
%D=[inf 7 8 2 inf inf 3 inf;
% 7 inf 1 inf 2 inf inf 3;
% 8 1 inf 4 2 7 inf inf;
% 2 inf 4 inf inf 4 6 inf;
% inf 2 2 inf inf 5 inf 1;
% inf inf 7 4 5 inf 4 3;
% 3 inf inf 6 inf 4 inf 6;
% inf 3 inf inf 1 3 6 inf];
%n=8;
% function [T c]=Primf1(D)
% n=length(D);
% T=[];l=0;%l记录T的列数
% q(1)=-1;
%for i=2:n
% p(i)=1;q(i)=D(i,1);
%end
%k=1;
%while 1
% if k>=n
% % disp(T);
% break;
% else
% min=inf;
% for i=2:n
% if q(i)>0&q(i)<min
% min=q(i);
% h=i;
% end
% end
% end
% l=l+1;
% T(1,l)=h;T(2,l)=p(h);
% q(h)=-1;
% for j=2:n
% if D(h,j)<q(j)
% q(j)=D(h,j);
% p(j)=h;
% end
% end
% k=k+1;
%end
%T;
%for g=1:n-1
% c(g)=a(T(1,g),T(2,g));
%end
%c;
