Submission #231381

#	Time	Username	Problem	Language	Result	Execution time	Memory
231381		maskoff	Bigger segments (IZhO19_segments)	C++14	73 / 100	593 ms	246432 KiB

segments

#include <bits/stdc++.h>
#include <ext/rope>
#include <random>
#include <chrono>
#include <ext/pb_ds/assoc_container.hpp>
 
#define file ""
 
#define all(x) x.begin(), x.end()
 
#define sc second
#define fr first
 
#define pb push_back
#define mp make_pair

#define pss pair<line*, line*>
 
using namespace std;
using namespace __gnu_cxx;
 
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
                                    
const ll inf = 1e18;
const int MOD = 1e9 + 7;
                                          
const int dx[] = {+1, -1, 0, 0};
const int dy[] = {0, 0, +1, -1};

int const N = 1e6 + 5;

vector<pll> t(4 * N + 20); 
int L[4 * N + 20], R[4 * N + 20];
int cnt = 1;

void update (int u, ll l, ll r, ll pos, pll val) {
	if(l > r) return;
 	if (l == r) {
 	 	t[u] = val;
 	 	return;
 	}
 	ll m = (l + r) / 2;
 	if (pos <= m) {
 	 	if (!L[u]) L[u] = ++cnt;
 	 	update (L[u], l, m, pos, val);
 	}
 	else {
 	 	if (!R[u]) R[u] = ++cnt;
 	 	update (R[u], m + 1, r, pos, val);
 	}
 	t[u] = max(t[L[u]], t[R[u]]);
}

pll get (int u, ll ul, ll ur, ll l, ll r) {
 	if (!u || l > r || ul > ur || l > ur || ul > r)
 		return {0, 0};
 	if (l <= ul && ur <= r)
 		return t[u];
 	ll um = (ul + ur) / 2;
 	return max(get(L[u], ul, um, l, r), get(R[u], um + 1, ur, l, r));
}

int main() {  
	ios_base :: sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  vector<int> a(N);
  for (int i = 1; i <= n; i++)
  	cin >> a[i];
  vector<ll> dp(N), sum(N), pref(N);
  for (int i = 1; i <= n; i++)
  	pref[i] = pref[i - 1] + a[i];

  for (int i = 1; i <= n; i++) {
  	pll k = get(1, 1, inf, 1, pref[i]);
  	dp[i] = k.fr + 1;
  	sum[i] = pref[i] - pref[k.sc];
  	update (1, 1, inf, sum[i] + pref[i], {dp[i], i});
  }
  cout << dp[n];
	return 0;
}

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