Submission #1071857

#	Time	Username	Problem	Language	Result	Execution time	Memory
1071857		mickey080929	Cultivation (JOI17_cultivation)	C++17	80 / 100	2045 ms	4880 KiB

cultivation

#include <bits/stdc++.h>
 
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pll;
 
const ll inf = 2e18;
 
ll R, C;
ll N;

ll mxl[310][310], mxr[310][310], mxsum[310][310];
 
ll solve(vector<pll> p, ll H) {
	vector<pll> upd;
	ll j = 0;
	for (ll i=0; i<p.size(); i++) {
		while (j < p.size() && p[j].first + H <= p[i].first) {
			upd.push_back({p[j].first + H, -p[j].second});
			j ++;
		}
		upd.push_back(p[i]);
	}
	while (j < p.size()) {
		upd.push_back({p[j].first + H, -p[j].second});
		j ++;
	}
	vector<array<ll,4>> save;
	ll idx1 = 0, idx2 = -1;
	for (ll i=0; i<upd.size(); i++) {
		if (upd[i].second > 0) idx2 ++;
		if (i + 1 != upd.size() && upd[i].first == upd[i+1].first) continue;
		while (idx1 < N && p[idx1].first + H <= upd[i].first) idx1 ++;
		if (idx1 > idx2) {
			save.push_back({upd[i].first, inf, inf, inf});
			continue;
		}
		save.push_back({upd[i].first, mxsum[idx1][idx2], mxl[idx1][idx2], mxr[idx1][idx2]});
	}
	ll ans = inf;
	deque<ll> dq[3];
	for (ll i=(ll)save.size()-1; i>=0; i--) {
		for (ll j=0; j<3; j++) {
			while (!dq[j].empty() && save[dq[j].back()][j+1] <= save[i][j+1]) {
				dq[j].pop_back();
			}
			while (!dq[j].empty() && save[dq[j].front()][0] > save[i][0] + R - 1) {
				dq[j].pop_front();
			}
			dq[j].push_back(i);
		}
		ans = min(ans, max(save[dq[0].front()][1], save[dq[1].front()][2] + save[dq[2].front()][3]));
	}
	return ans;
}
 
int main() {
    ios_base :: sync_with_stdio(false); cin.tie(NULL);
    cin >> R >> C;
    cin >> N;
    vector<pll> p(N);
    for (ll i=0; i<N; i++) {
    	cin >> p[i].first >> p[i].second;
    }
    sort(p.begin(), p.end());
    for (ll i=0; i<N; i++) {
    	multiset<ll> s1, s2;
    	for (ll j=i; j<N; j++) {
    		if (!s1.empty()) {
				auto rit = s1.lower_bound(p[j].second);
				if (rit != s1.begin()) {
					auto lit = prev(rit);
					if (rit != s1.end()) {
						s2.erase(s2.find(*rit - *lit));
					}
					s2.insert(p[j].second - *lit);
				}
				if (rit != s1.end()) {
					s2.insert(*rit - p[j].second);
				}
			}
			s1.insert(p[j].second);
    		mxl[i][j] = *s1.begin() - 1, mxr[i][j] = C - *s1.rbegin();
			mxsum[i][j] = mxl[i][j] + mxr[i][j];
			if (!s2.empty()) mxsum[i][j] = *s2.rbegin() - 1;
    	}
    }
    vector<ll> cand, U, D;
    for (ll i=0; i<N; i++) {
    	U.push_back(p[i].first - 1);
    	D.push_back(R - p[i].first);
    	for (ll j=i+1; j<N; j++) {
    		cand.push_back(abs(p[i].first - p[j].first));
    	}
    }
    for (auto &u : U) {
    	for (auto &d : D) {
    		cand.push_back(u + d + 1);
    	}
    }
    sort(cand.begin(), cand.end());
    cand.erase(unique(cand.begin(), cand.end()), cand.end());
    ll ans = inf;
    for (auto &H : cand) {
   		if (H == 0) continue;
    	ans = min(ans, H - 1 + solve(p, H));
    }
    cout << ans << '\n';
}

Compilation message (stderr)

cultivation.cpp: In function 'll solve(std::vector<std::pair<long long int, long long int> >, ll)':
cultivation.cpp:18:16: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |  for (ll i=0; i<p.size(); i++) {
      |               ~^~~~~~~~~
cultivation.cpp:19:12: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |   while (j < p.size() && p[j].first + H <= p[i].first) {
      |          ~~^~~~~~~~~~
cultivation.cpp:25:11: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |  while (j < p.size()) {
      |         ~~^~~~~~~~~~
cultivation.cpp:31:16: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |  for (ll i=0; i<upd.size(); i++) {
      |               ~^~~~~~~~~~~
cultivation.cpp:33:13: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |   if (i + 1 != upd.size() && upd[i].first == upd[i+1].first) continue;
      |       ~~~~~~^~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 30 / 30
• Subtask 5: 20 / 20
• Subtask 6: 0 / 20