Submission #705416

#	Time	Username	Problem	Language	Result	Execution time	Memory
705416		pavement	Bigger segments (IZhO19_segments)	C++17	13 / 100	182 ms	262144 KiB

segments

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//~ #define int long long
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define g0(a) get<0>(a)
#define g1(a) get<1>(a)
#define g2(a) get<2>(a)
#define g3(a) get<3>(a)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
using db = double;
using ll = long long;
using ld = long double;
using ii = pair<int, int>;
using iii = tuple<int, int, int>;
using iiii = tuple<int, int, int, int>;
template<class key, class value = null_type, class cmp = less<key> >
using ordered_set = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;

int n, a[500005];
ll p[500005];
pair<int, ll> dp[500005];

struct node {
	node *left, *right;
	ll S, E;
	pair<int, ll> val;
	node(ll _s, ll _e) : left(nullptr), right(nullptr), S(_s), E(_e), val(-(ll)1e16, -(ll)1e16) {}
	void upd(ll p, pair<int, ll> v) {
		val = max(val, v);
		if (S == E) return;
		int M = (S + E) / 2;
		if (p <= M) {
			if (left == nullptr) left = new node(S, M);
			left->upd(p, v);
		} else {
			if (right == nullptr) right = new node(M + 1, E);
			right->upd(p, v);
		}
	}
	pair<int, ll> qry(ll p) {
		if (p < S) return mp(-1, -(ll)1e16);
		if (E <= p) return val;
		return max(left == nullptr ? mp(-1, -(ll)1e16) : left->qry(p), right == nullptr ? mp(-1, -(ll)1e16) : right->qry(p));
	}
} *root;

main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n;
	root = new node(-(ll)1e16, (ll)1e16);
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		p[i] = a[i] + p[i - 1];
		assert(-(ll)1e16 <= p[i] && p[i] <= (ll)1e16);
		auto tmp = root->qry(p[i]);
		tmp.second -= p[i];
		dp[i] = max(mp(1, -p[i]), tmp);
		assert(-(ll)1e16 <= p[i] - dp[i].second && p[i] - dp[i].second <= (ll)1e16);
		root->upd(p[i] - dp[i].second, mp(dp[i].first + 1, p[i]));
	}
	cout << dp[n].first << '\n';
}

Compilation message (stderr)

segments.cpp:54:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   54 | main() {
      | ^~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27