Submission #1071909

#	Time	Username	Problem	Language	Result	Execution time	Memory
1071909		mickey080929	Cultivation (JOI17_cultivation)	C++17	100 / 100	1769 ms	3548 KiB

cultivation

#include <bits/stdc++.h>

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("Ofast")
 
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;
	upd.reserve(N * 2);
	ll j = 0;
	for (ll i=0; i<N; i++) {
		while (j < N && 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 < N) {
		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<N*2; i++) {
		if (upd[i].second > 0) idx2 ++;
		if (i + 1 != N*2 && 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;
}

ll solve2(vector<pll> &p, ll H1, ll H2) {
	vector<pll> upd;
	ll j = 0;
	for (ll i=0; i<N; i++) {
		while (j < N && p[j].first + H2 + 1 <= p[i].first - H1) {
			upd.push_back({p[j].first + H2 + 1, -p[j].second});
			j ++;
		}
		upd.push_back({max(1LL, p[i].first - H1), p[i].second});
	}
	while (j < N) {
		upd.push_back({p[j].first + H2 + 1, -p[j].second});
		j ++;
	}
	if (upd[0].first != 1) return inf;
	ll l = 0, r = 0, sum = 0;
	ll idx1 = 0, idx2 = -1;
    for (ll i=0; i<upd.size(); i++) {
        if (upd[i].first > R) break;
        if (upd[i].second > 0) idx2 ++;
        else idx1 ++;
        if (i + 1 != upd.size() && upd[i].first == upd[i+1].first) continue;
        if (idx1 > idx2) {
            return inf;
        }
        l = max(l, mxl[idx1][idx2]);
        r = max(r, mxr[idx1][idx2]);
        sum = max(sum, mxsum[idx1][idx2]);
    }
    return max(sum, l+r);
}
 
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++) {
    	vector<ll> cur;
    	for (ll j=i; j<N; j++) {
    		if (cur.empty() || cur.back() < p[j].second) {
    			cur.push_back(p[j].second);
    		}
    		else {
    			for (ll k=0; k<cur.size(); k++) {
    				if (cur[k] >= p[j].second) {
    					cur.insert(cur.begin() + k, p[j].second);
    					break;
    				}
    			}
    		}
    		ll l = cur[0] - 1, r = C - cur.back();
			ll sum = 0;
			for (ll k=0; k+1<cur.size(); k++) {
				sum = max(sum, cur[k+1] - cur[k] - 1);
			}
			mxl[i][j] = l; mxr[i][j] = r;
			mxsum[i][j] = sum;
    	}
    }
    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));
    	}
    }
    sort(cand.begin(), cand.end());
    cand.erase(unique(cand.begin(), cand.end()), cand.end());
    sort(U.begin(), U.end());
    U.erase(unique(U.begin(), U.end()), U.end());
    sort(D.begin(), D.end());
    D.erase(unique(D.begin(), D.end()), D.end());
    ll ans = inf;
    for (auto &H : cand) {
   		if (H == 0) continue;
    	ans = min(ans, H - 1 + solve(p, H));
    }
    for (auto &u : U) {
    	for (auto &d : D) {
    		ans = min(ans, u + d + solve2(p, u, d));
    	}
    }
    cout << ans << '\n';
}

Compilation message (stderr)

cultivation.cpp: In function 'll solve2(std::vector<std::pair<long long int, long long int> >&, ll, ll)':
cultivation.cpp:80:19: 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]
   80 |     for (ll i=0; i<upd.size(); i++) {
      |                  ~^~~~~~~~~~~
cultivation.cpp:84:19: 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]
   84 |         if (i + 1 != upd.size() && upd[i].first == upd[i+1].first) continue;
      |             ~~~~~~^~~~~~~~~~~~~
cultivation.cpp: In function 'int main()':
cultivation.cpp:111:22: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |        for (ll k=0; k<cur.size(); k++) {
      |                     ~^~~~~~~~~~~
cultivation.cpp:120:20: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |    for (ll k=0; k+1<cur.size(); k++) {
      |                 ~~~^~~~~~~~~~~

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