Submission #236421

#	Time	Username	Problem	Language	Result	Execution time	Memory
236421		_7_7_	Bigger segments (IZhO19_segments)	C++14	100 / 100	161 ms	20984 KiB

segments

#include <bits/stdc++.h>                                           
 
#define int long long
//#pragma GCC optimize("Ofast")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")
 
 
#define file(s) freopen(s".in","r",stdin); freopen(s".out","w",stdout);
#define forev(i, b, a) for(int i = (b); i >= (a); --i)
#define forn(i, a, b) for(int i = (a); i <= (b); ++i)
#define all(x) x.begin(), x.end()
#define sz(s) (int)s.size()
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define s second
#define f first
 
 
using namespace std;
 
 
typedef pair < long long, long long > pll;    
typedef pair < int, int > pii;
typedef unsigned long long ull;         
typedef vector < pii > vpii;
typedef vector < int > vi;
typedef long double ldb;  
typedef long long ll;  
typedef double db;                             
 
 
const int inf = 1e9, maxn = 4e5 + 148, mod = 1e9 + 7, N = 5e5 + 11;
const int dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1}, block = 555;
const pii base = mp(1171, 3307), Mod = mp(1e9 + 7, 1e9 + 9);
const db eps = 1e-12, pi = 3.14159265359;
const ll INF = 1e18;


int n, a[N], dp[N];
pii t[N];

void inc (int pos, pii x) {
	while (pos < N) {
		t[pos] = max(t[pos], x);
		pos |= pos + 1;
	}	
}

pii get (int r) {
	pii res = {0, 0};
	while (r >= 0) {
		res = max(res, t[r]);    
		r = (r & (r + 1)) - 1;
	}

	return res;
}

                                                  
main () {
	scanf("%lld", &n);
	for (int i = 1; i <= n; ++i) {
		scanf("%lld", &a[i]);
		a[i] += a[i - 1];	
	}

	for (int i = 1; i <= n; ++i) {
		pii cur = get(i);
		dp[i] = cur.f + 1;

		int j = lower_bound(a + 1, a + 1 + n, a[i]*2 - a[cur.s]) - a;
		inc(j, {dp[i], i});
	}

	cout << dp[n] << endl;
}

Compilation message (stderr)

segments.cpp:62:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^
segments.cpp: In function 'int main()':
segments.cpp:63:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld", &n);
  ~~~~~^~~~~~~~~~~~
segments.cpp:65:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld", &a[i]);
   ~~~~~^~~~~~~~~~~~~~~

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