Submission #828949

#	Time	Username	Problem	Language	Result	Execution time	Memory
828949		OAleksa	Watching (JOI13_watching)	C++14	0 / 100	36 ms	744 KiB

watching

#include <bits/stdc++.h>
#define f first
#define s second
using namespace std; 
#define int long long

signed main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int tt = 1;
	//cin >> tt;
	while(tt--) {
		int n, p, q;
		cin >> n >> p >> q;
		vector<int> a(n);
		for(int i = 0;i < n;i++)
			cin >> a[i];
		sort(a.begin(), a.end());
		auto intersect = [&](int x1, int y1, int x2, int y2) {
			if(y1 < x2 || x1 > y2)
				return 0ll;
			return min(y2, y1) - max(x1, x2) + 1;
		};
		auto check = [&](int x) {
			set<pair<int, int>> d, d1;
			for(int i = 0;i < n;i++) {
				auto u = upper_bound(a.begin(), a.end(), a[i] + 2 * x - 1) - a.begin();
				--u;
				d.emplace(u - i + 1, i);
			}
			vector<int> vis(n);
			for(int i = 0;i < min(n, q);i++) {
				auto u = *--d.end();
				d.erase(--d.end());
				for(int j = u.s, k = 0;k < u.f;k++,j++)
					vis[j] = 1;
				set<pair<int, int>> t = d;
				for(auto x : t) {
					int l = x.s, r = x.s + x.f - 1;
					int k = intersect(l, r, u.s, u.f + u.s - 1);
					d.erase({x.f, x.s});
					d.insert({x.f - k, l});
				}
			}
			vector<int> pr(n);
			pr[0] = vis[0];
			for(int i = 1;i < n;i++)
				pr[i] = pr[i - 1] + vis[i];
			for(int i = 0;i < n;i++) {
				auto u = upper_bound(a.begin(), a.end(), a[i] + x - 1) - a.begin();
				--u;
				d1.emplace(u - i + 1 - pr[u] + (i == 0 ? 0 : pr[i - 1]), i);
			}
			for(int i = 0;i < min(n, p);i++) {
				auto u = *--d1.end();
				d1.erase(--d1.end());
				for(int j = u.s, k = 0;k < u.f;k++,j++)
					vis[j] = 1;
				set<pair<int, int>> t = d1;
				for(auto x : t) {
					int l = x.s, r = x.s + x.f - 1;
					int k = intersect(l, r, u.s, u.f + u.s - 1);
					d1.erase({x.f, x.s});
					d1.insert({x.f - k, l});
				}
			}
			int ok = 1;
			for(int i = 0;i < n;i++)
				ok &= (vis[i] == 1);
			return ok;
		};
		int l = 1, r = 1e9, ans = -1;
		while(l <= r) {
			int mid = (l + r) / 2;
			if(check(mid)) {
				ans = mid;
				r = mid - 1;
			}
			else
				l = mid + 1;
		}
		cout << ans << "\n";
	}
   return 0;
}

• Subtask 1: 0 / 50
• Subtask 2: 0 / 50