# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
33921 | petil | Split the sequence (APIO14_sequence) | C11 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
struct CHT{
struct line{
ll s, t;
int idx;
};
deque<line> que;
bool ck(line L1, line L2, line me){
///x1 = (L1.t-L2.t) /(L2.s-L1.s)
///x2 = (L2.t - me.t) / (me.s-L2.s)
///x1<x2
return (L1.t-L2.t) * (me.s-L2.s) < (L2.t-me.t) * (L2.s-L1.s) ;
}
void push(line me){
while((int)que.size()>=2 && !ck(que[(int)que.size()-2], que.back(), me)){
que.pop_back();
}
if(!que.empty() && que.back().s == me.s){
if(que.back().t>=me.t)return;
que.pop_back();que.push_back(me);
}
else{
que.push_back(me);
}
}
ll val(line li, ll x)
{
return li.s * x + li.t;
}
void Efront(ll x)
{
while((int)que.size()>=2 && !(val(que[0], x)>val(que[1], x))){
// if(que[1].idx == id)return;
que.pop_front();
}
}
ll maxval(ll x, ll tt){
return tt + val(que[0], x);
}
};
int n, k, A[100005];
ll rs[100005], dp[100005];
int pre[100003][202];
void trace(int now, int j)
{
vector<int> tmp;
while(1){
if(j==0)break;
tmp.push_back(now);
now = pre[now][j];--j;
}
for(int i=(int)tmp.size()-1; i>=0; i--)
cout<<tmp[i]<<" ";
}
int main()
{
scanf("%d %d", &n, &k);
for(int i=1; i<=n; i++){
scanf("%d", &A[i]);
}
for(int i=n; i>=1; i--){
rs[i] = rs[i+1]+(ll)A[i];
}
vector<pair<pair<ll ,ll>, int> > tmp;
tmp.push_back({{-rs[1], 0}, 0});
for(int j=1; j<=k; j++){
CHT cht;
int pos = 0;
vector<pair<pair<ll ,ll>, int> > tmp2;
for(int i=j; i<=n; i++){
while(pos<(int)tmp.size() && tmp[pos].second<i){
cht.push({tmp[pos].first.first, tmp[pos].first.second, tmp[pos].second});
++pos;
}
cht.Efront(-rs[i+1]);
dp[i] = cht.maxval(-rs[i+1], -(ll)rs[i+1]*rs[i+1]);
///nxt.push({-rs[i+1], dp[i], i});
tmp2.push_back({{-rs[i+1], dp[i]}, i});
pre[i][j] = cht.que[0].idx;
}
tmp.clear();
tmp = tmp2;
}
ll ans=-1, ed=-1;
for(int i=k; i<=n; i++){
if(ans<dp[i]){
ans = dp[i];ed=i;
}
}
cout<<ans<<endl;
trace(ed, k);
}