VPARTSUM - Tổng bộ phận
Tác giả: flashmt
Ngôn ngữ: Pascal
uses math;
const fi='';
maxn=100100;
var n,z,k,re,num:longint;
a:array[0..maxn*2] of longint;
b,c,d:array[0..maxn] of longint;
procedure rf;
var x,i:longint;
begin
read(n,k,z);
re:=z-1;
for i:=1 to n do
begin
read(x);
x:=x mod z;
if x>=k then re:=min(re,x);
a[i]:=(a[i-1]+x) mod z;
d[i]:=i;
end;
end;
procedure sort(l,r:longint);
var i,j,x,y,t:longint;
begin
i:=l; j:=r; x:=a[(i+j) shr 1]; y:=d[(j+i) shr 1];
repeat
while (a[i]<x) or ((a[i]=x) and (d[i]<y)) do i:=i+1;
while (a[j]>x) or ((a[j]=x) and (d[j]>y)) do j:=j-1;
if i<=j then
begin
t:=a[i]; a[i]:=a[j]; a[j]:=t;
t:=d[i]; d[i]:=d[j]; d[j]:=t;
i:=i+1; j:=j-1;
end;
until i>j;
if i<r then sort(i,r);
if l<j then sort(l,j);
end;
function bs(val,l:longint):longint;
var r,m,i:longint;
begin
r:=l+num;
while l<=r do
begin
m:=(l+r) shr 1;
if a[m]<val then l:=m+1
else r:=m-1;
end;
for i:=m-1 to m+1 do
if (i>=0) and (i<=num*2+1) and (a[i]>=val) then exit(i mod (num+1));
end;
procedure pr;
var i,x:longint;
begin
sort(0,n);
num:=0;
for i:=1 to n do
if a[i]>a[num] then
begin
num:=num+1;
a[num]:=a[i];
b[num]:=d[i];
c[num-1]:=d[i-1];
end;
c[num]:=d[n];
for i:=0 to num do a[num+1+i]:=a[i]+z;
for i:=0 to num do
begin
x:=bs(a[i]+k,i);
while ((a[x]-a[i]+z) mod z<re) do
begin
if b[i]<c[x] then
begin
re:=(a[x]-a[i]+z) mod z;
break;
end;
x:=(x+1) mod (num+1);
end;
if re=k then break;
end;
writeln(re);
end;
begin
assign(input,fi); reset(input);
rf;
pr;
close(input);
end.