Submission #35037

#	Time	Username	Problem	Language	Result	Execution time	Memory
35037		UncleGrandpa925	Watching (JOI13_watching)	C++14	100 / 100	303 ms	33584 KiB

watching

/*input
3 1 1
2
11
17
*/
#include <bits/stdc++.h>
using namespace std;
#define sp ' '
#define endl '\n'
#define fi first
#define se second
#define mp make_pair
#define int long long
#define N 2005
#define bit(x,y) ((x>>y)&1LL)
#define na(x) (#x) << ":" << x
ostream& operator << (ostream &os, vector<int>&x) {
	for (int i = 0; i < x.size(); i++) os << x[i] << sp;
	return os;
}
ostream& operator << (ostream &os, pair<int, int> x) {
	cout << x.fi << sp << x.se << sp;
	return os;
}
ostream& operator << (ostream &os, vector<pair<int, int> >&x) {
	for (int i = 0; i < x.size(); i++) os << x[i] << endl;
	return os;
}

int n, P, Q;
vector<int> a;
vector<pair<int, int> > nxt;
int dp[N][N];

bool check(int lim) {
	nxt.clear(); memset(dp, -1, sizeof(dp));
	for (int i = 0; i < a.size(); i++) {
		auto it = upper_bound(a.begin(), a.end(), a[i] + lim - 1);
		it--;
		pair<int, int> ret = mp(0, 0); ret.fi = it - a.begin();
		it = upper_bound(a.begin(), a.end(), a[i] + 2 * lim - 1);
		it--;
		ret.se = it - a.begin();
		nxt.push_back(ret);
	}
	for (int i = 0; i <= P; i++) {
		for (int j = 0; j <= Q; j++) {
			if (dp[i][j] == a.size() - 1) return true;
			if (i != P) {
				dp[i + 1][j] = max(dp[i + 1][j], nxt[dp[i][j] + 1].fi);
			}
			if (j != Q) {
				dp[i][j + 1] = max(dp[i][j + 1], nxt[dp[i][j] + 1].se);
			}
		}
	}
	return false;
}

signed main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n >> P >> Q;
	a.resize(n);
	for (auto &t : a) cin >> t;
	sort(a.begin(), a.end());
	a.resize(distance(a.begin(), unique(a.begin(), a.end())));
	P = min(P, n); Q = min(Q, n);
	int l = 1, r = 1e9;
	while (l != r) {
		int mid = (l + r) / 2;
		if (check(mid)) r = mid;
		else l = mid + 1;
	}
	cout << l << endl;
}

Compilation message (stderr)

watching.cpp: In function 'std::ostream& operator<<(std::ostream&, std::vector<long long int>&)':
watching.cpp:19:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < x.size(); i++) os << x[i] << sp;
                    ^
watching.cpp: In function 'std::ostream& operator<<(std::ostream&, std::vector<std::pair<long long int, long long int> >&)':
watching.cpp:27:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < x.size(); i++) os << x[i] << endl;
                    ^
watching.cpp: In function 'bool check(long long int)':
watching.cpp:38:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < a.size(); i++) {
                    ^
watching.cpp:49:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if (dp[i][j] == a.size() - 1) return true;
                 ^

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