Submission #397892

#	Time	Username	Problem	Language	Result	Execution time	Memory
397892		ritul_kr_singh	Untitled (POI11_tem)	C++17	92 / 100	535 ms	36688 KiB

Main

#include <bits/stdc++.h>
using namespace std;
// #define int long long
#define sp << ' ' <<
#define nl << '\n'

const int INF = 2e9;

struct SegmentTree{
	vector<int> a; int sz = 1;
	SegmentTree(int n){
		while(sz < n) sz += sz;
		a.assign(2*sz, -INF);
	}
	void update(int i, int v, int x, int lx, int rx){
		if(rx-lx==1) return void(a[x] = v);
		int mx = (lx + rx) / 2;
		if(i < mx) update(i, v, 2*x+1, lx, mx);
		else update(i, v, 2*x+2, mx, rx);
		a[x] = max(a[2*x+1], a[2*x+2]);
	}
	void update(int i, int v){ update(i, v, 0, 0, sz); }
	int firstGreater(int v, int x, int lx, int rx){
		if(rx-lx==1) return lx;
		int mx = (lx + rx) / 2;
		if(a[2*x+1] > v) return firstGreater(v, 2*x+1, lx, mx);
		else return firstGreater(v, 2*x+2, mx, rx);
	}
	int firstGreater(int v){ return firstGreater(v, 0, 0, sz); }
};

signed main(){
	cin.tie(0)->sync_with_stdio(0);
	int n; cin >> n;
	int l[n], r[n], k = n;

	vector<int> s;

	for(int i=0; i<n; ++i) cin >> l[i] >> r[i];

	SegmentTree st(n+1);
	
	for(int i=n-1; i>=0; --i){
		int j = min(n, st.firstGreater(-l[i]));
		st.update(i, -r[i]);
		r[i] = j - i;

		while(!s.empty() and l[s.back()] <= l[i]) s.pop_back();

		if(!s.empty() && s.back() < j) r[i] = r[s.back()] + (int)s.back() - i;

		s.push_back(i);
	}

	cout << *max_element(r, r+n);	
}

Compilation message (stderr)

tem.cpp: In function 'int main()':
tem.cpp:35:18: warning: unused variable 'k' [-Wunused-variable]
   35 |  int l[n], r[n], k = n;
      |                  ^

• Subtask 1: 8 / 8
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 8 / 8
• Subtask 5: 8 / 8
• Subtask 6: 8 / 8
• Subtask 7: 0 / 8
• Subtask 8: 8 / 8
• Subtask 9: 9 / 9
• Subtask 10: 9 / 9
• Subtask 11: 9 / 9
• Subtask 12: 9 / 9