Submission #1127225

#	Time	Username	Problem	Language	Result	Execution time	Memory
1127225		RiverFlow	Tricks of the Trade (CEOI23_trade)	C++20	20 / 100	7875 ms	4608 KiB

trade

#include <bits/stdc++.h>

#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())

using namespace std;

template<typename U, typename V> bool maxi(U &a, V b) {
    if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
    if (a > b) { a = b; return 1; } return 0;
}

const int N = (int)250000 + 9;
const int mod = (int)1e9 + 7;

void prepare(); void main_code();

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    const bool MULTITEST = 0; prepare();
    int num_test = 1; if (MULTITEST) cin >> num_test;
    while (num_test--) { main_code(); }
}

void prepare() {};

int n, k, c[N];
long long s[N];

const long long INF = -(long long)1e15;

namespace DNC {
long long ans = INF;

int ar[N];
long long f[N], g[N];

void solve(int l, int r) {
    if (r - l + 1 < k) return ;
    int m = (l + r) >> 1;
    int d = 0;
    FOR(i, 1, k) f[i] = INF;
    for(int i = m; i >= l; --i) {
        int p = -1;
        if (d == 0 or c[i] <= ar[d]) {
            ar[++d] = c[i];
        } else {
            // c[i]>ar[d]
            for(int j = 0; j < d; ++j) if (c[i] > ar[j + 1]) {
                for(int k = d; k > j; --k)
                    ar[k+1] = ar[k];
                ar[j+1] = c[i];
                ++d;
                break ;
            }
            d = min(d, k);
        }
        long long sum = 0;
        for(int j = 1; j <= d; ++j) {
            sum += ar[j];
            maxi(f[j], s[i-1] + sum);
        }
    }
    FOR(i, 1, k) g[i] = INF;
    d = 0;
    for(int i = m + 1; i <= r; ++i) {
        if (d == 0 or c[i] <= ar[d]) {
            ar[++d] = c[i];
        } else {
            // c[i]>ar[d]
            for(int j = 0; j < d; ++j) if (c[i] > ar[j + 1]) {
                for(int k = d; k > j; --k)
                    ar[k+1] = ar[k];
                ar[j+1] = c[i];
                ++d;
                break ;
            }
            d = min(d, k);
        }
        long long sum = 0;
        for(int j = 1; j <= d; ++j) {
            sum += ar[j];
            maxi(g[j], -s[i] + sum);
        }
    }
    f[0] = s[m - 1];
    g[0] = -s[m + 1];
//    FOR(i, 0, k) cout << f[i] << ' '; cout << nl;
//    FOR(i, 0, k) cout << g[i] << ' '; cout << nl;
//    cout << nl;
    for(int j = 0; j <= min(k, m - l + 1); ++j) {
        maxi(ans, f[j] + g[k - j]);
    }
    solve(l, m);
    solve(m + 1, r);
}
void sol() {
    solve(1, n);
    cout << ans << nl;
}
};

void main_code() {
    cin >> n >> k;
    FOR(i, 1, n) cin >> s[i], s[i] += s[i - 1];
    FOR(i, 1, n) cin >> c[i];

    if (k <= 200) {
        DNC::sol();
        return ;
    }

}


/*     Let the river flows naturally     */

Compilation message (stderr)

trade.cpp: In function 'int main()':
trade.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
trade.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 10
• Subtask 2: 0 / 10
• Subtask 3: 5 / 10
• Subtask 4: 10 / 25
• Subtask 5: 0 / 45