[code deleted]

Edited by moderator 24.11.2019 13:21

You have overflow:

...
up:=1;
for down:=1 to n do begin
sum:=b[j,down]-b[j,up-1]-b[i-1,down]+b[i-1,up-1];
...

In first step b[j,up-1] = b[j][0] but b is
array[1..maxn,1..maxn] of longint (0 is invalid)

Thanks, but after chaging
a,b:array[1..maxn,1..maxn] of longint
to
a,b:array[0..maxn,0..maxn] of longint
i also have WA3

Thanks, I got AC.
My problem: I wroute : up:=down;
            But need : up:=down+1;