제출 #97723

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
97723		dalgerok	수열 (APIO14_sequence)	C++14	100 / 100	760 ms	84692 KiB

sequence

#include<bits/stdc++.h>
using namespace std;


const int N = 1e5 + 5;


int n, m, a[N], pref[N];
int pr[202][N];


struct line{
    long long k, b;
    int pos;
    inline long long val(int x){
        return k * x + b;
    }
};
line q1[N], q2[N];
int sz1, sz2;

inline long long intersect(line l1, line l2){
    return (l1.b - l2.b) / (l2.k - l1.k);
}
inline bool Is_need_to_erase(line l1, line l2, line l3){
    long long x = intersect(l1, l3);
    return l2.val(x) <= l3.val(x);
}
inline void Add(line new_line){
    if(sz1 && q1[sz1 - 1].k == new_line.k){
        if(q1[sz1 - 1].b < new_line.b){
            sz1 -= 1;
        }
        else{
            return;
        }
    }
    while(sz1 > 2 && Is_need_to_erase(q1[sz1 - 2], q1[sz1 - 1], new_line)){
        sz1 -= 1;
    }
    q1[sz1] = new_line;
    sz1 += 1;
}

inline void Swap(){
    swap(q1, q2);
    swap(sz1, sz2);
    sz1 = 0;
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin >> n >> m;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
    }
    for(int i = 1; i <= n; i++){
        Add({pref[i], -(1LL * pref[i] * pref[i]), i});
    }
    Swap();
    long long ans = 0;
    for(int i = 1; i <= m; i++){
        int pos = 0;
        for(int j = i + 1; j <= n; j++){
            while(pos + 1 < sz2 && q2[pos + 1].pos < j && q2[pos].val(pref[j]) <= q2[pos + 1].val(pref[j])){
                pos += 1;
            }
            pr[i][j] = q2[pos].pos;
            ans = q2[pos].val(pref[j]);
            Add({pref[j], ans - 1LL * pref[j] * pref[j], j});
        }
        Swap();
    }
    cout << ans << "\n";
    vector < int > anss;
    for(int i = m, x = n; x && i >= 1; i--){
        x = pr[i][x];
        anss.push_back(x);
    }
    reverse(anss.begin(), anss.end());
    for(auto it : anss){
        cout << it << " ";
    }
}

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