var sum,s,n,i,j,k:longint; a:array[1..100]of longint;
begin
 read(s,n);
 for i:=1 to s do read(a[i]);
 for j:=1 to s do
   for i:=1 to j do
    begin  sum:=0;
     for k:=i to j do sum:=sum+a[k];
     if sum>j-i+n+1 then begin write('NO'); exit; end;
    end;
 write('Yes');
end.

Think about simpler solution -> without array - just O(n) !!

I got AC without any array! )

var sum,s,n,i,j,k:longint; a:array[1..30000]of longint;
begin
read(s,n);
for i:=1 to s do read(a[i]);
for j:=1 to s do
for i:=1 to j do
begin sum:=0;
for k:=i to j do sum:=sum+a[k];
if sum>j-i+n+1 then begin write('NO'); exit; end;
end;
write('YES');
end.

var sum,s,n,i,j,k:longint; a:array[1..30000]of longint;
begin
read(s,n);
for i:=1 to s do read(a[i]);
for j:=1 to s do
for i:=1 to j do
begin sum:=0;
for k:=i to j do sum:=sum+a[k];
if sum>j-i+n+1 then begin write('NO'); exit; end;
end;
write('YES');
end.

use
 for i:=1 to s do
  for j:=i to s do
   begin
    ....
   end;

{1<=i<=j<=s}