Submission #138163

#	Time	Username	Problem	Language	Result	Execution time	Memory
138163		muradeyn	Split the sequence (APIO14_sequence)	C++14	71 / 100	299 ms	131072 KiB

sequence

/* Murad Eynizade */

#include <bits/stdc++.h>
#define int long long
#define FAST_READ ios_base::sync_with_stdio(0);cin.tie(0);
#define F first
#define S second
//#define endl '\n'

using namespace std;

const int maxx = 100005;

int n , k , idx;

int dp[maxx][201] , pre[maxx] , arr[maxx] , sz[201] , in[201];

vector< pair< int , pair<int,int> > >v[201];

int inter(pair<int,int>a,pair<int,int>b) {
    return (a.S - b.S) / (b.F - a.F);
}

pair<int,int> sec(int i) {
    pair< int , pair<int,int> >t , ret;
    t = v[i].back(); v[i].pop_back();
    ret = v[i].back(); v[i].push_back(t);
    return ret.S;
}

main() {
    FAST_READ
    cin>>n>>k;
    for (int i = 1;i<=n;i++)cin>>arr[i] , pre[i] = pre[i - 1] + arr[i];
    for (int j = 1;j<=n;j++) {
        dp[j][1] = pre[j] * (pre[n] - pre[j]);
        int i = 1;
        pair<int,int>line = {pre[j] , -pre[j] * pre[n] + dp[j][1]};
        while (sz[i] >= 2) {
            pair<int,int>tp = v[i].back().S;
            pair<int,int>tp2 = sec(i);
            if (tp.F == line.F) {
                v[i].pop_back();
                sz[i]--;
                continue;
            }
            int inter1 = inter(tp , tp2);
            int inter2 = inter(tp2 , line);
            if (inter2 < inter1)v[i].pop_back() , sz[i]--;
            else {
                break;
            }
        }
        if (sz[i]) {
            pair< int , pair<int,int> >cur = v[i].back();
            v[i].pop_back();
            sz[i]--;
            if (cur.S.F != line.F) {
                cur.F = inter(line , cur.S);
                v[i].push_back(cur);
                sz[i]++;
            }
        }
        v[i].push_back({1000000001 , line});
        sz[i]++;
    }
    for (int j = 2;j<=k;j++) {
        for (int i = j;i<=n;i++) {
            while (in[j - 1] < sz[j - 1] && v[j - 1][in[j - 1]].F < pre[i])in[j - 1]++;
            pair< int , pair<int,int> >cur = v[j - 1][in[j - 1]];
            dp[i][j] = cur.S.F * pre[i] + cur.S.S + pre[i] * pre[n] - pre[i] * pre[i];
            int ii = j;
            pair<int,int>line = {pre[i] , -pre[i] * pre[n] + dp[i][j]};
            while (sz[ii] >= 2) {
                pair<int,int>tp = v[ii].back().S;
                pair<int,int>tp2 = sec(ii);
                if (tp.F == line.F) {
                    v[ii].pop_back();
                    sz[ii]--;
                    continue;
                }
                int inter1 = inter(tp , tp2);
                int inter2 = inter(tp2 , line);
                if (inter2 < inter1)v[ii].pop_back() , sz[ii]--;
                else {
                    break;
                }
            }
            if (sz[ii]) {
                pair< int , pair<int,int> >cur = v[ii].back();
                v[ii].pop_back();
                sz[ii]--;
                if (cur.S.F != line.F) {
                    cur.F = inter(line , cur.S);
                    v[ii].push_back(cur);
                    sz[ii]++;
                }
            }
            v[ii].push_back({1000000001 , line});
            sz[ii]++;
        }
    }
    idx = -1;
    for (int i = 1;i<=n;i++) {
        if (idx == -1)idx = i;
        if (dp[i][k] > dp[idx][k])idx = i;
    }
    cout<<dp[idx][k]<<endl;
    vector<int>res;
    res.push_back(idx);
    k--;
    while (k) {
        for (int ii = idx;ii;ii--) {
            if (dp[ii - 1][k] + (pre[idx] - pre[ii - 1]) * (pre[n] - pre[idx]) == dp[idx][k + 1]) {
                idx = ii - 1;
                break;
            }
        }
        res.push_back(idx);
        k--;
    }
    reverse(res.begin(),res.end());
    for (int i : res)cout<<i<<" ";
    cout<<endl;
}

Compilation message (stderr)

sequence.cpp:31:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main() {
      ^

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