Submission #556680

# Submission time Handle Problem Language Result Execution time Memory
556680 2022-05-03T15:32:24 Z timreizin Split the sequence (APIO14_sequence) C++17
100 / 100
723 ms 87288 KB
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")

#include <iostream>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <string>
#include <numeric>
#include <cmath>
#include <cassert>
#include <array>
#include <numeric>

using namespace std;

using ll = long long;

const ll INF = 1e18;

struct Line
{
    ll k, b;
    int who;
    
    Line(ll k = 0, ll b = 0, int who = 0) : k(k), b(b), who(who)
    {}
    
    ll operator()(ll x)
    {
        return k * x + b;
    }
    
};

bool check(Line a, Line b, Line c)
{
    if (b.k == c.k) return b.b >= c.b;
    return (__int128)(a.b - c.b) * (b.k - a.k) <= (__int128)(a.b - b.b) * (c.k - a.k);
}

int main()
{
    cin.tie(0)->sync_with_stdio(0);
    int n, k;
    cin >> n >> k;
    ++k;
    vector<ll> a(n);
    for (ll &i : a) cin >> i;
    array<vector<ll>, 2> dp;
    dp[0] = dp[1] = vector<ll>(n + 1, INF);
    dp[0][0] = 0;
    ll res = accumulate(a.begin(), a.end(), 0ll);
    res = res * res;
    partial_sum(a.begin(), a.end(), a.begin());
    a.insert(a.begin(), 0);
    vector<vector<int>> parent(n + 1, vector<int>(k, -1));
    auto dac = [&dp, &a, &parent](auto self, int l, int r, int l2, int r2, int level)
    {
        if (l > r) return;
        int m = (l + r) >> 1, ind = l2;
        for (int i = l2; i <= min(r2, m - 1); ++i)
        {
            ll cur = dp[0][i] + (a[m] - a[i]) * (a[m] - a[i]);
            if (cur < dp[1][m])
            {
                dp[1][m] = cur;
                ind = i;
            }
        }
        parent[m][level] = ind;
        self(self, l, m - 1, l2, ind, level);
        self(self, m + 1, r, ind, r, level);
    };
    for (int i = 0; i < k; ++i)
    {
        //dac(dac, i + 1, n, 0, n - 1, i);
        deque<Line> dq;
        dq.push_back({-2 * a[i], dp[0][i] + a[i] * a[i], i});
        for (int j = i + 1; j <= n; ++j)
        {
            while (dq.size() >= 2 && dq[0](a[j]) > dq[1](a[j])) dq.pop_front();
            dp[1][j] = dq.front()(a[j]) + a[j] * a[j];
            parent[j][i] = dq.front().who;
            //add
            Line add{-2 * a[j], dp[0][j] + a[j] * a[j], j};
            while (dq.size() >= 2 && check(dq[(int)dq.size() - 2], dq.back(), add)) dq.pop_back();
            if (dq.back().k != add.k) dq.push_back(add);
        }
        //i -> i + 1
        dp[0] = dp[1];
        dp[1] = vector<ll>(n + 1, INF);
    }
    vector<int> path(k - 1);
    for (int i = k - 1, v = n; i > 0; v = parent[v][i], --i) path[k - i - 1] = parent[v][i];
    cout << (res - dp[0].back()) / 2 << '\n';
    reverse(path.begin(), path.end());
    for (int i : path) cout << i << ' ';
    return 0;
}
/*dp[i] = min j < i
    dp[j] + (p[i] - p[j])^2 = dp[j] + p[j]^2 - 2p[j]*p[i] + p[i]^2
    kx + b*/
/*
4
1 3
4
0 2 3
*/

Compilation message

sequence.cpp: In function 'int main()':
sequence.cpp:59:10: warning: variable 'dac' set but not used [-Wunused-but-set-variable]
   59 |     auto dac = [&dp, &a, &parent](auto self, int l, int r, int l2, int r2, int level)
      |          ^~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB contestant found the optimal answer: 108 == 108
2 Correct 1 ms 324 KB contestant found the optimal answer: 999 == 999
3 Correct 1 ms 324 KB contestant found the optimal answer: 0 == 0
4 Correct 1 ms 320 KB contestant found the optimal answer: 1542524 == 1542524
5 Correct 1 ms 320 KB contestant found the optimal answer: 4500000000 == 4500000000
6 Correct 1 ms 212 KB contestant found the optimal answer: 1 == 1
7 Correct 1 ms 212 KB contestant found the optimal answer: 1 == 1
8 Correct 1 ms 212 KB contestant found the optimal answer: 1 == 1
9 Correct 0 ms 212 KB contestant found the optimal answer: 100400096 == 100400096
10 Correct 1 ms 316 KB contestant found the optimal answer: 900320000 == 900320000
11 Correct 1 ms 212 KB contestant found the optimal answer: 3698080248 == 3698080248
12 Correct 1 ms 212 KB contestant found the optimal answer: 3200320000 == 3200320000
13 Correct 1 ms 324 KB contestant found the optimal answer: 140072 == 140072
14 Correct 1 ms 320 KB contestant found the optimal answer: 376041456 == 376041456
15 Correct 1 ms 320 KB contestant found the optimal answer: 805 == 805
16 Correct 1 ms 212 KB contestant found the optimal answer: 900189994 == 900189994
17 Correct 0 ms 212 KB contestant found the optimal answer: 999919994 == 999919994
# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB contestant found the optimal answer: 1093956 == 1093956
2 Correct 0 ms 212 KB contestant found the optimal answer: 302460000 == 302460000
3 Correct 1 ms 212 KB contestant found the optimal answer: 122453454361 == 122453454361
4 Correct 1 ms 212 KB contestant found the optimal answer: 93663683509 == 93663683509
5 Correct 1 ms 212 KB contestant found the optimal answer: 1005304678 == 1005304678
6 Correct 1 ms 312 KB contestant found the optimal answer: 933702 == 933702
7 Correct 1 ms 212 KB contestant found the optimal answer: 25082842857 == 25082842857
8 Correct 1 ms 212 KB contestant found the optimal answer: 687136 == 687136
9 Correct 1 ms 212 KB contestant found the optimal answer: 27295930079 == 27295930079
10 Correct 1 ms 212 KB contestant found the optimal answer: 29000419931 == 29000419931
# Verdict Execution time Memory Grader output
1 Correct 1 ms 244 KB contestant found the optimal answer: 610590000 == 610590000
2 Correct 1 ms 340 KB contestant found the optimal answer: 311760000 == 311760000
3 Correct 2 ms 448 KB contestant found the optimal answer: 1989216017013 == 1989216017013
4 Correct 1 ms 340 KB contestant found the optimal answer: 1499437552673 == 1499437552673
5 Correct 1 ms 340 KB contestant found the optimal answer: 1019625819 == 1019625819
6 Correct 1 ms 468 KB contestant found the optimal answer: 107630884 == 107630884
7 Correct 1 ms 468 KB contestant found the optimal answer: 475357671774 == 475357671774
8 Correct 1 ms 340 KB contestant found the optimal answer: 193556962 == 193556962
9 Correct 1 ms 312 KB contestant found the optimal answer: 482389919803 == 482389919803
10 Correct 1 ms 320 KB contestant found the optimal answer: 490686959791 == 490686959791
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB contestant found the optimal answer: 21503404 == 21503404
2 Correct 1 ms 340 KB contestant found the optimal answer: 140412195 == 140412195
3 Correct 7 ms 1108 KB contestant found the optimal answer: 49729674225461 == 49729674225461
4 Correct 1 ms 340 KB contestant found the optimal answer: 37485571387523 == 37485571387523
5 Correct 6 ms 1108 KB contestant found the optimal answer: 679388326 == 679388326
6 Correct 5 ms 980 KB contestant found the optimal answer: 4699030287 == 4699030287
7 Correct 7 ms 1092 KB contestant found the optimal answer: 12418819758185 == 12418819758185
8 Correct 5 ms 1108 KB contestant found the optimal answer: 31093317350 == 31093317350
9 Correct 2 ms 468 KB contestant found the optimal answer: 12194625429236 == 12194625429236
10 Correct 3 ms 724 KB contestant found the optimal answer: 12345131038664 == 12345131038664
# Verdict Execution time Memory Grader output
1 Correct 3 ms 1228 KB contestant found the optimal answer: 1818678304 == 1818678304
2 Correct 3 ms 1364 KB contestant found the optimal answer: 1326260195 == 1326260195
3 Correct 51 ms 9044 KB contestant found the optimal answer: 4973126687469639 == 4973126687469639
4 Correct 3 ms 1364 KB contestant found the optimal answer: 3748491676694116 == 3748491676694116
5 Correct 41 ms 5844 KB contestant found the optimal answer: 1085432199 == 1085432199
6 Correct 47 ms 6612 KB contestant found the optimal answer: 514790755404 == 514790755404
7 Correct 48 ms 7144 KB contestant found the optimal answer: 1256105310476641 == 1256105310476641
8 Correct 38 ms 5972 KB contestant found the optimal answer: 3099592898816 == 3099592898816
9 Correct 44 ms 6724 KB contestant found the optimal answer: 1241131419367412 == 1241131419367412
10 Correct 54 ms 8148 KB contestant found the optimal answer: 1243084101967798 == 1243084101967798
# Verdict Execution time Memory Grader output
1 Correct 25 ms 10100 KB contestant found the optimal answer: 19795776960 == 19795776960
2 Correct 26 ms 10240 KB contestant found the optimal answer: 19874432173 == 19874432173
3 Correct 577 ms 87288 KB contestant found the optimal answer: 497313449256899208 == 497313449256899208
4 Correct 25 ms 10588 KB contestant found the optimal answer: 374850090734572421 == 374850090734572421
5 Correct 723 ms 87040 KB contestant found the optimal answer: 36183271951 == 36183271951
6 Correct 515 ms 63304 KB contestant found the optimal answer: 51629847150471 == 51629847150471
7 Correct 527 ms 68524 KB contestant found the optimal answer: 124074747024496432 == 124074747024496432
8 Correct 441 ms 57404 KB contestant found the optimal answer: 309959349080800 == 309959349080800
9 Correct 445 ms 63532 KB contestant found the optimal answer: 124113525649823701 == 124113525649823701
10 Correct 558 ms 79288 KB contestant found the optimal answer: 124309619349406845 == 124309619349406845