type
 node=record
       d:integer;
       n:longint;
      end;
var
 dl:array [1..100000] of node;
 l,le:array [1..1000] of longint;
 able:array [1..1000] of integer;
 i,n,m,f,t,k:longint;

This program I got "Memory Limit Exceeded 15 1153 КБ"

Then I change the node
 node=record
       d:word;
       n:longint;
      end;
I got AC.

What is the difference between using word and integer?
Each of them is 2 bytes. I changed integer to word myself and I got AC too.

In some compilers integer and longint have the same size. If you want a 2 byte integer I think you can use smallint.