Submission #595448

#	Time	Username	Problem	Language	Result	Execution time	Memory
595448		shrimb	Split the sequence (APIO14_sequence)	C++17	50 / 100	2080 ms	7912 KiB

sequence

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

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template<class x>
using ordered_set = tree<x, null_type,less<x>, rb_tree_tag,tree_order_statistics_node_update>;

#define int long long
#define endl '\n'
#define mod 1000000007
//\
#define mod 1686876991

const int maxn = 100001;
int n, k;

int a[maxn];
int p[maxn];

int dp[201][maxn];
int opts[201][maxn];

int cost (int l, int r) {
    // cerr << "cost(" << l << "," << r << "): " << (p[r] - (l ? p[l - 1] : 0)) * (p[n-1] - p[r]) << endl;
    return (p[r] - (l ? p[l - 1] : 0)) * (p[n-1] - p[r]);
}

void rec (int l, int r, int lk, int rk, int j) {
    if (r < l) return;
    int m = (l + r) / 2;
    int opt;
    dp[j][m] = -INT_MAX;
    for (int K = j - 1; K <= min(rk, m) ; K++) {
        if ((K ? dp[j - 1][K-1] : 0) + cost(K, m) > dp[j][m]) {
            opt = K;
            dp[j][m] = (K ? dp[j - 1][K - 1] : 0) + cost(K, m);
        }
    }
    opts[j][m] = opt;
    rec(l, m - 1, lk, opt, j);
    rec(m + 1, r, opt, rk, j);
}

signed main () {
    cin.tie(0)->sync_with_stdio(0);
    cin >> n >> k;

    for (int i = 0 ; i < n ; i++) {
        cin >> a[i];
        p[i] = a[i];
        if (i) p[i] += p[i-1];
    }

    for (int i = 0 ; i < n ; i++) {
        dp[1][i] = cost(0, i);
    }
    for (int i = 2 ; i <= k + 1 ; i++) {
        rec(0, n - 1, 0, n - 1, i);
    }
    cout << dp[k + 1][n-1] << endl;
    int i = k + 1;
    int j = n - 1;
    vector<int> v;
    while (i > 1) {
        v.push_back(opts[i][j]);
        j = opts[i][j] - 1;
        i--;
    }
    reverse(v.begin(), v.end());
    for (int i : v) cout << i << " ";
}

Compilation message (stderr)

sequence.cpp:14:1: warning: multi-line comment [-Wcomment]
   14 | //\
      | ^
sequence.cpp: In function 'void rec(long long int, long long int, long long int, long long int, long long int)':
sequence.cpp:43:8: warning: 'opt' may be used uninitialized in this function [-Wmaybe-uninitialized]
   43 |     rec(l, m - 1, lk, opt, j);
      |     ~~~^~~~~~~~~~~~~~~~~~~~~~

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