题面：
思路：
代码：
uses math;
var ans,n,m,tot,x,y,i,j:longint;
next,last,tail:array[0..100005] of longint;
t,c,d:array[0..10005] of longint;
f:Array[0..10005] of boolean;
procedure add(x,y:longint);
begin
inc(tot);
next[tot]:=y;
last[tot]:=tail[x];
tail[x]:=tot;
end;
procedure dfs(x,y:longint);
var cc:longint;
begin
c[x]:=max(c[x],y+t[x]);
dec(d[x]);
if d[x]=0 then
begin
cc:=tail[x];
while (cc>0) do
begin
dfs(next[cc],c[x]);
cc:=last[cc];
end;
end;
end;
begin
assign(input,'msched.in');
reset(input);
assign(output,'msched.out');
rewrite(output);
read(n,m);
for i:=1 to n do read(t[i]);
for i:=1 to m do begin read(x,y); add(x,y); f[y]:=true; inc(d[y]); end;
for i:=1 to n do
if not f[i] then
begin
d[i]:=1;
dfs(i,0);
end;
for i:=1 to n do ans:=max(ans,c[i]);
writeln(ans);
close(input);close(output);
end.
