Submission #856716

#	Time	Username	Problem	Language	Result	Execution time	Memory
856716		Amirreza_Fakhri	Split the sequence (APIO14_sequence)	C++17	100 / 100	788 ms	82720 KiB

sequence

// In the name oF the God 
#include <bits/stdc++.h>
#define ll long long
#define int long long
#define pb push_back
#define F first
#define S second
#define mp make_pair
#define pii pair <int, int>
#define smin(x, y) (x) = min((x), (y))
#define smax(x, y) (x) = max((x), (y))
#define halt(x) cout << x << '\n', exit(0)
using namespace std;

const int inf = 1e9 + 7;
const int mod = 998244353;
const int maxN = 1e5 + 5, maxK = 2e2 + 5;

int n, k, ps[maxN], dp[2][maxN];
int32_t opt[maxK][maxN];

int cost(int l, int r) {
    return ps[l] * (ps[r] - ps[l]);
}

void optimize(int q, int l, int r, int optl, int optr) {
    int mid = (r + l) >> 1, o;
    for (int i = optl; i < min(mid, optr); i++) {
        if (dp[1][mid] <= dp[0][i] + cost(i, mid)) {
            dp[1][mid] = dp[0][i] + cost(i, mid);
            o = i;
        }
    }
    if (r - l == 1) {
        opt[q][mid] = o;
        return;
    }
    optimize(q, l, mid, optl, o + 1);
    optimize(q, mid, r, o, optr);
}

void f(int pos, int q) {
    if (!q) return;
    cout << pos << ' ';
    f(opt[q][pos], q - 1);
}

int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n >> k; k++;
    for (int i = 1; i <= n; i++) {
        cin >> ps[i]; ps[i] += ps[i-1];
    }
    for (int i = 0; i <= n; i++) dp[0][i] = dp[1][i] = -inf * inf;
    dp[0][0] = 0;
    for (int i = 1; i <= k; i++) {
        optimize(i, i, n + 1, 0, n);
        for (int i = 0; i <= n; i++) dp[0][i] = dp[1][i];
        for (int i = 0; i <= n; i++) dp[1][i] = -inf * inf;
    }
    cout << dp[0][n] << '\n';
    f(opt[k][n], k - 1);
    cout << '\n';
    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'void optimize(long long int, long long int, long long int, long long int, long long int)':
sequence.cpp:38:13: warning: 'o' may be used uninitialized in this function [-Wmaybe-uninitialized]
   38 |     optimize(q, l, mid, optl, o + 1);
      |     ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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