Submission #126957

#	Time	Username	Problem	Language	Result	Execution time	Memory
126957		AQT	Split the sequence (APIO14_sequence)	C++14	22 / 100	1338 ms	31224 KiB

sequence

#include <bits/stdc++.h>

using namespace std;

int N, K;
long long pre[100005];
long long dp[100005][25];
int par[100005][25];
deque<int>dq;

double f(int idx1, int idx2, int lvl){
    return (dp[idx1][lvl]-dp[idx2][lvl]-pre[idx1]*pre[idx1]+pre[idx2]*pre[idx2]);
}

int main(){
    cin.sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> N >> K;
    for(int i = 1; i<=N; i++){
        cin >> pre[i];
        pre[i] += pre[i-1];
    }
    for(int k = 1; k<=K; k++){
        dq.push_back(k);
        for(int i = k+1; i<=N; i++){
            while(dq.size() >= 2){
                if(f(dq[0], dq[1], k-1) <= pre[i]*(pre[dq[1]]-pre[dq[0]])){
                    dq.pop_front();
                }
                else{
                    break;
                }
            }
            dp[i][k] = dp[dq.front()][k-1] + pre[dq.front()]*(pre[i]-pre[dq.front()]);
            par[i][k] = dq.front();
            //cout << i << " " << k << " " << dp[i][k] << " " << par[i][k] << endl;
            while(dq.size() >= 2){
                if(f(dq[dq.size()-2], dq[dq.size()-1], k-1)*(pre[i]-pre[dq.back()])
                   >= f(dq.back(), i, k-1)*(pre[dq[dq.size()-1]]-pre[dq[dq.size()-2]])){
                    dq.pop_back();
                }
                else{
                    break;
                }
            }
            dq.push_back(i);
        }
        dq.clear();
    }
    cout << dp[N][K] << "\n";
    int crnt = N;
    for(int k = K; k>=1; k--){
        cout << par[crnt][k] << " ";
        crnt = par[crnt][k];
    }
    cout << "\n";
}

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