Submission #342537

#	Time	Username	Problem	Language	Result	Execution time	Memory
342537		NurstanDuisengaliev	Bigger segments (IZhO19_segments)	C++14	37 / 100	223 ms	72172 KiB

segments

// Nurstan Duisengaliev
// не, не надо меня узнавать 
/*#pragma GCC target ("avx2")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("O3")*/                   
      
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp> 
 
#define ll long long
#define all(x) x.begin(), x.end()
#define in insert
#define mp make_pair
#define F first
#define S second
#define ppf pop_front
#define pb push_back
#define ppb pop_back
#define pf push_front
#define pii pair <int, int>
#define pll pair <ll, ll>
#define boost() ios_base::sync_with_stdio(0), cin.tie(0)
#define sz(x) (int)x.size()
 
using namespace std;
//using namespace __gnu_pbds;
 
//template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;                         
 
const int N = 3005;
const int mod = (int)1e9 + 7;
const ll INF = (ll)1e18 + 1;
int n;
ll a[N], pref[N]; 
int dp[N][N];
void solve () {
	cin >> n;
	for (int i = 1; i <= n; i ++) {
		cin >> a[i];
		pref[i] = pref[i - 1] + a[i];
		for (int j = 1; j <= n; j ++) dp[i][j] = -1;
		dp[i][i] = 1;
	}                                         	
	for (int i = 1; i < n; i ++) {                            
		for (int j = 1; j <= i; j ++) { 
			ll x = pref[i] - pref[i - j];
			if (dp[i][j] != -1) {
				dp[i + 1][j + 1] = max (dp[i + 1][j + 1], dp[i][j]);
				int pos = -1;
				int l = i + 1, r = n;
				while (l <= r) {         
					int mid = l + r >> 1;
					if (pref[mid] - pref[i] >= x) {
						r = mid - 1;
						pos = mid;
					}
					else {
						l = mid + 1;
					}
				}
				if (pos != -1) dp[pos][pos - i] = max (dp[pos][pos - i], dp[i][j] + 1);
			}
		}
	}
	int maxi = 0;
	for (int i = 1; i <= n; i ++) {
		maxi = max (maxi, dp[n][i]);
	}
	cout << maxi;
}   	
 
main () {
//	freopen (".in", "r", stdin);
//	freopen (".out", "w", stdout);
	boost ();
	int TT = 1;
//    cin >> TT;
	while (TT --) {
		solve ();
	}
	return 0;	                                    
}                                                   

Compilation message (stderr)

segments.cpp: In function 'void solve()':
segments.cpp:55:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   55 |      int mid = l + r >> 1;
      |                ~~^~~
segments.cpp: At global scope:
segments.cpp:75:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   75 | main () {
      |       ^

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