Submission #344906

#	Time	Username	Problem	Language	Result	Execution time	Memory
344906		spike1236	Split the sequence (APIO14_sequence)	C++14	100 / 100	1438 ms	81204 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define ll long long
#define ld long double
#define all(_v) _v.begin(), _v.end()
#define sz(_v) (int)_v.size()
#define pii pair <int, int>
#define pll pair <ll, ll>
#define veci vector <int>
#define vecll vector <ll>


const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
const double PI = 3.1415926535897932384626433832795;
const double eps = 1e-9;
const int MOD1 = 1e9 + 7;
const int MOD2 = 998244353;

const int MAXN = 1e5 + 10;
ll pref[MAXN];
ll dp[2][MAXN];
int opt[220][MAXN];
int n, K;

void calc(int k, int l, int r, int optl, int optr) {
    if(l > r) return;
    int m = l + r >> 1;
    ll res = -1e18;
    opt[k][m] = optl;
    for(int i = optl; i <= min(m - 1, optr); ++i) {
        ll cur = dp[(k & 1) ^ 1][i] + pref[i] * (pref[m] - pref[i]);
        if(cur > res) {
            res = cur;
            opt[k][m] = i;
        }
    }
    dp[k & 1][m] = res;
    calc(k, l, m - 1, optl, opt[k][m]);
    calc(k, m + 1, r, opt[k][m], optr);
}


void solve() {
    cin >> n >> K;
    for(int i = 1; i <= n; ++i) {
        ll x;
        cin >> x;
        pref[i] = pref[i - 1] + x;
    }
    for(int i = 1; i <= K; ++i)
        calc(i, 1, n, 1, n);
    cout << dp[K & 1][n] << '\n';
    int pos = n;
    for(int i = K; i > 0; --i)
        pos = opt[i][pos], cout << pos << ' ';
}


int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int T = 1;
    ///cin >> T;
    while(T--) solve(), cout << '\n';
    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'void calc(int, int, int, int, int)':
sequence.cpp:32:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   32 |     int m = l + r >> 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