| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 804914 | flappybird | Cultivation (JOI17_cultivation) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#include <cassert>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define MAX 660
#define MAXS 20
#define INF 20000000000020
#define bb ' '
#define ln '\n'
#define Ln '\n'
#define MOD 1000000007
ll H, W;
int N;
pll arr[MAX];
ll ans = INF;
int st[MAX * 2], en[MAX * 2];
int U[MAX], D[MAX], UD[MAX];
int A[MAX][MAX], B[MAX][MAX], C[MAX][MAX];
typedef pair<ll, int> pli;
pii up[MAX * 2], down[MAX * 2], su[MAX * 2];
ll ys[MAX * 2];
bool test(ll d) {
if (d <= 0) return false;
int i, j;
int p1, p2;
p1 = p2 = 1;
int X = 0;
while (p1 <= N || p2 <= N) {
ll x;
if (p1 > N) x = arr[p2].second + d;
else if (p2 > N) x = arr[p1].second;
else x = min(arr[p1].second, arr[p2].second + d);
st[X] = en[X] = 0;
U[X] = D[X] = UD[X] = 0;
ys[X++] = x;
while (p1 <= N && arr[p1].second == x) p1++, st[X - 1]++;
while (p2 <= N && arr[p2].second + d == x) p2++, en[X - 1]++;
}
int il, ir;
il = ir = 0;
for (i = 0; i < X; i++) {
ir += st[i];
il += en[i];
if (il == ir) {
UD[i] = INF;
continue;
}
U[i] = A[il + 1][ir];
D[i] = B[il + 1][ir];
UD[i] = C[il + 1][ir];
}
int ul, dl, udl;
int ur, dr, udr;
ul = dl = udl = 0;
ur = dr = udr = 0;
int mn = H * 2 + 10;
j = 0;
for (i = 0; i < X - 1; i++) {
while (ul != ur && up[ur].first <= U[i]) ur--;
up[++ur] = pli(U[i], i);
while (dl != dr && down[dr].first <= D[i]) dr--;
down[++dr] = pli(D[i], i);
while (udl != udr && su[udr].first <= UD[i]) udr--;
su[++udr] = pli(UD[i], i);
while (j + 1 <= i && ys[i + 1] - ys[j + 1] >= W) j++;
while (ul != ur && up[ul + 1].second < j) ul++;
while (dl != dr && down[dl + 1].second < j) dl++;
while (udl != udr && su[udl + 1].second < j) udl++;
if (ys[i + 1] - ys[j] >= W) mn = min(mn, max(up[ul + 1].first + down[dl + 1].first, su[udl + 1].first));
}
if (mn >= H * 2) return false;
ans = min(ans, mn + d - 1);
return true;
}
signed main() {
ios::sync_with_stdio(false), cin.tie(0);
cin >> H >> W >> N;
int i, j, k;
vector<ll> ls;
ls.push_back(W);
for (i = 1; i <= N; i++) cin >> arr[i].first >> arr[i].second;
for (i = 1; i <= N; i++) {
for (j = i + 1; j <= N; j++) ls.push_back(W - abs(arr[j].second - arr[i].second));
for (j = i + 1; j <= N; j++) ls.push_back(abs(arr[j].second - arr[i].second));
for (j = i + 1; j <= N; j++) ls.push_back(abs(arr[j].second - arr[i].second) + W);
ls.push_back(arr[i].second);
ls.push_back(W - arr[i].second + 1);
}
sort(arr + 1, arr + N + 1, [&](pii p1, pii p2) {return p1.second < p2.second; });
for (i = 1; i <= N; i++) {
vector<ll> v;
A[i][i] = arr[i].first - 1;
B[i][i] = H - arr[i].first;
v.push_back(arr[i].first);
for (j = i + 1; j <= N; j++) {
v.insert(lower_bound(v.begin(), v.end(), arr[j].first), arr[j].first);
for (k = 0; k + 1 < v.size(); k++) C[i][j] = max(C[i][j], v[k + 1] - v[k] - 1);
A[i][j] = v[0] - 1;
B[i][j] = H - v.back();
}
}
sort(ls.begin(), ls.end());
ls.erase(unique(ls.begin(), ls.end()), ls.end());
reverse(ls.begin(), ls.end());
for (auto v : ls) if (!test(v)) break;
cout << ans << ln;
}