Submission #541756

#	Time	Username	Problem	Language	Result	Execution time	Memory
541756		FatihSolak	Split the sequence (APIO14_sequence)	C++17	71 / 100	178 ms	131072 KiB

sequence

#include <bits/stdc++.h>
#define N 100005
#define K 205
using namespace std;
long long dp[N][K];
int par[N][K];
long long pre[N];
struct CHT{
    vector<pair<pair<int,int>,pair<int,long long>>> lines;
    long long get(pair<int,long long> a,pair<int,long long> b){
        if(a.first == b.first)
            return 0;
        return (b.second - a.second + (a.first - b.first -1)) / (a.first - b.first);
    }
    void add(int a,long long b,int c){
        if(lines.size() && lines.back().second.first == a && lines.back().second.second >= b)
            return;
        while(lines.size() && get(lines.back().second,{a,b}) <= lines.back().first.first){
            lines.pop_back();
        }
        if(lines.empty()){
            lines.push_back({{0,c},{a,b}});
        }
        else lines.push_back({{get(lines.back().second,{a,b}),c},{a,b}});
    }
    pair<int, long long> get(int x){
        pair<pair<int,int>,pair<int,long long>> tmp = {{x+1,0},{0,0}};
        int pos = lower_bound(lines.begin(),lines.end(),tmp) - lines.begin() - 1;
        return {lines[pos].first.second,1ll * lines[pos].second.first * x + lines[pos].second.second};
    }
}maxi[K];
void solve(){
    int n,k;
    cin >> n >> k;
    k++;
    for(int i = 1;i<=n;i++){
        cin >> pre[i];
        pre[i] += pre[i-1];
    }
    maxi[0].add(0,0,0);
    for(int i=1;i<=k;i++){
        maxi[i].add(0,-1e9,-1e18);
    }
    for(int i=1;i<=n;i++){
        for(int j = k;j>=1;j--){
            auto x = maxi[j-1].get(pre[i]);
            par[i][j] = x.first;
            dp[i][j] = x.second - pre[i] * pre[i] + pre[i] * pre[n];
            maxi[j].add(2*pre[i], dp[i][j] - pre[i] * pre[n] - pre[i] * pre[i],i);
        }    
    }
    cout << dp[n][k] / 2 << endl;
    while(par[n][k]){
        cout << par[n][k];
        n = par[n][k];
        k--;
        if(k)cout << " ";
    }
}

int32_t main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    #ifdef Local
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
    #endif
    int t=1;
    //cin>>t;
    while(t--){
        solve();
    }
    #ifdef Local
    cout<<endl<<fixed<<setprecision(2)<<1000.0 * clock() / CLOCKS_PER_SEC<< " milliseconds ";
    #endif
}

Compilation message (stderr)

sequence.cpp: In function 'void solve()':
sequence.cpp:42:28: warning: overflow in conversion from 'double' to 'int' changes value from '-1.0e+18' to '-2147483648' [-Woverflow]
   42 |         maxi[i].add(0,-1e9,-1e18);
      |                            ^~~~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 0 / 29