Submission #1010912

#	Time	Username	Problem	Language	Result	Execution time	Memory
1010912		ByeWorld	Money (IZhO17_money)	C++14	100 / 100	1010 ms	69972 KiB

money

#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
#define ll long long
#define int long long
#define pb push_back
#define fi first
#define se second
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
#define ld long double
using namespace std;
typedef pair<int,int> pii;
typedef pair<pii, int> ipii;
const int MAXN = 1e6+20;
const int MAXA = 9e3+20;
const ll INF = 1e18+10;
const int LOG = 19;
const int MOD = 1e9+7;
const int SQRT = 450;
const vector<int> NOL = {};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const vector<int> dx = {1, -1, 0, 0};
const vector<int> dy = {0, 0, 1, -1};

int n;
int a[MAXN], dp[MAXN];
set <int> s;

signed main(){
	cin >> n;
	int cnt = 0;
	for(int i=1; i<=n; i++) {
		int x; cin >> x;
		if(x != a[cnt]) a[++cnt] = x;
	}
	n = cnt;
	int las = 1;
	for(int i=1; i<=n; i++){
		if(a[i-1] > a[i]){
			for(int j=las; j<=i-1; j++) s.insert(a[j]);
			las = i;
		}
		// cout << las << ' ' << i << " las\n";
		int less = -INF; 
		auto it = s.lower_bound(a[i]);
		if(it != s.begin()) less = *(--it);
		// cout << less << " les\n";
		int l=las, r=i, mid=0, cnt=i;
		while(l <= r){
			mid = md;
			auto nw = s.upper_bound(a[mid]);
			if(nw == s.begin()){
				if(less == -INF){ cnt = mid; r = mid-1; }
				else l = mid+1;
			} else {
				if(less == *(--nw)){ cnt = mid; r = mid-1; }
				else l = mid+1;
			}
		}
		// cout << cnt << "cnt\n";
		dp[i] = dp[cnt-1]+1;
	}
	cout << dp[n] << '\n';
}

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 20 / 20
• Subtask 4: 55 / 55