Submission #580885

#	Time	Username	Problem	Language	Result	Execution time	Memory
580885		drdilyor	Divide and conquer (IZhO14_divide)	C++17	100 / 100	36 ms	6220 KiB

divide

#if defined(ONPC) && !defined(_GLIBCXX_ASSERTIONS)
    #define _GLIBCXX_ASSERTIONS
#endif
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>
#ifdef ONPC
    #include "t_debug.cpp"
#else
    #define debug(...) 42
#endif
#define allit(a) (a).begin(), (a).end()
#define sz(a) ((int) (a).size())

using namespace std;
using ll = long long;
using vi = vector<int>;
namespace pd = __gnu_pbds;
template<typename K>
using ordered_set = pd::tree<K, pd::null_type, less<int>, pd::rb_tree_tag, pd::tree_order_statistics_node_update>;
template<typename... T>
using gp_hash_table = pd::gp_hash_table<T...>;//simple using statement gives warnings

const int INF = 1e9;
const ll INFL = 1e18;
const int N = 1e5;
const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
mt19937 rng(RANDOM);

template<typename T>
struct SegTree {
    int n;
    vector<T> tree;
    SegTree(int n, T def) : n(n), tree(n*2, def) {}
    void set(int i, T v) { tree[i+n] = v; }
    void build() {
        for (int i = n-1; i >= 1; i--) {
            tree[i] = max(tree[i*2], tree[i*2+1]);
        }
    }
    int query(T x) {
        int v = 1;
        while (v < n) {
            if (tree[v*2+1] >= x) v = v*2 + 1;
            else if (tree[v*2] >= x) v = v * 2;
            else return -1;
        }
        return v - n;
    }
};

int nextPower2(int n) {
    n--;
    n |= n >> 1;
    n |= n >> 2;
    n |= n >> 4;
    n |= n >> 8;
    n |= n >> 16;
    return 1 + n;
}

int solve() {
    int n; cin >> n;
    vi x(n), g(n), d(n);
    for (int i = 0; i < n; i++) cin >> x[i] >> g[i] >> d[i];

    vector<ll> prefg(n+1), prefd(n+1);
    for (int i = 0; i < n; i++) {
        prefg[i+1] = prefg[i] + g[i];
        prefd[i+1] = prefd[i] + d[i];
    }

    vector<ll> diff(n);
    SegTree<ll> tree(nextPower2(n), -INFL);
    for (ll i = 0, energy = 0; i < n; i++) {
        energy += d[i];
        energy -= x[i] - x[max(0LL, i-1)];
        diff[i] = energy;
        tree.set(i, diff[i]);
    }
    tree.build();


    ll res = 0;
    for (int i = 0; i < n; i++) {
        int find = diff[i] - d[i];
        int index = tree.query(find);
        assert(index >= i);
        res = max(res, prefg[index+1] - prefg[i]);
    }
    debug(diff);
    cout << res;
    return 0;
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);
    int t = 1;
    //cin >> t;
    while (t-- && cin) {
        if (solve()) break;
        #ifdef ONPC
            cout << "____________________" << endl;
        #endif
    }
    return 0;
}

Compilation message (stderr)

divide.cpp: In function 'int solve()':
divide.cpp:10:24: warning: statement has no effect [-Wunused-value]
   10 |     #define debug(...) 42
      |                        ^~
divide.cpp:91:5: note: in expansion of macro 'debug'
   91 |     debug(diff);
      |     ^~~~~

• Subtask 1: 17 / 17
• Subtask 2: 31 / 31
• Subtask 3: 52 / 52