工厂的烦恼

题意：

思路：

const
maxn=100;
manv=1000;
var
a:array [0..maxn,0..maxn] of longint;
x,y,i,j,n,m,k,z,max,s:longint;
begin
readln(n,m);
fillchar(a,sizeof(a),250);
for i:=1 to m do
begin
readln(x,y,z);
a[x,y]:=z;
end;
for k:=1 to n do
for i:=1 to n do
for j:=1 to n do
if (k<>i) and (i<>j) and (j<>k) then
if (a[i,j]<a[i,k]+a[k,j]) and (a[i,k]>-5201314) and (a[k,j]>-5201314) then
a[i,j]:=a[i,k]+a[k,j];
max:=-maxlongint;
for i:=1 to n do
for j:=1 to n do
if a[i,j]>max then max:=a[i,j];
writeln(max);
end.