# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1017709 | cadmiumsky | Rectangles (IOI19_rect) | 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 "towers.h"
#include <vector>
#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
using namespace std;
using ll = long long;
using ld = long double;
#define int ll
#define sz(x) ((int)(x).size())
using pii = pair<int,int>;
using tii = tuple<int,int,int>;
const int nmax = 1e5 + 5;
int v[nmax];
namespace DSU {
int dsu[nmax], nxt[nmax];
int mxR[nmax];
void init(int l, int r) {
for(int i = l; i <= r; i++) dsu[i] = i, nxt[i] = i + 1;
return;
}
int f(int x) { return x == dsu[x]? x : dsu[x] = f(dsu[x]); }
void unite(int x, int y) {
x = f(x);
y = f(y);
if(x == y) return;
if(x > y) swap(x, y);
dsu[y] = x;
mxR[x] = max(mxR[x], mxR[y]);
nxt[x] = nxt[y];
return;
}
int coef(int i, const vector<int>& p) {
i = f(i);
return mxR[i] - max(v[p[i]], v[p[nxt[i]]]);
}
}
int timeout[nmax];
int dir[nmax];
void initglobals(signed L, signed R) {
++L;
++R;
vector<int> p;
for(int i = L; i <= R; i++) {
if((i == L || v[i] < v[i - 1]) && (i == R || v[i] < v[i + 1])) p.emplace_back(i), timeout[i] = 1e9 + 5;
else timeout[i] = 0;
}
DSU::init(0, sz(p));
set<pii> heap;
set<int> indemnizatii;
for(int i = 0; i < sz(p) - 1; i++) {
indemnizatii.emplace(i);
indemnizatii.emplace(i + 1);
int mx = v[p[i] + 1];
for(int j = p[i] + 2; j < p[i + 1]; j++)
mx = max(mx, v[j]);
DSU::mxR[i] = mx;
heap.emplace(mx - max(v[p[i]], v[p[i + 1]]), i);
}
auto get = [&](int p_) { return pii{DSU::coef(p_, p), p_}; };
while(!heap.empty()) {
auto [C, i] = *heap.begin();
heap.erase(heap.begin());
i = DSU::f(i);
int urm = DSU::nxt[i];
if(i != *indemnizatii.begin()) {
int ant = DSU::f(i - 1);
heap.erase(heap.find(get(ant)));
}
if(urm != *indemnizatii.rbegin())
heap.erase(heap.find(get(urm)));
if(v[p[i]] < v[p[urm]]) {
timeout[p[urm]] = C;
dir[p[urm]] = p[i];
DSU::unite(i, urm);
indemnizatii.erase(urm);
if(i != *indemnizatii.begin()) {
int ant = DSU::f(i - 1);
heap.insert(get(ant));
}
if(i != *indemnizatii.rbegin())
heap.insert(get(i));
}
else {
timeout[p[i]] = C;
dir[p[i]] = p[urm];
if(i != *indemnizatii.begin()) {
int ant = DSU::f(i - 1);
DSU::unite(ant, i);
heap.insert(get(ant));
}
if(urm != *indemnizatii.rbegin())
heap.insert(get(urm));
indemnizatii.erase(i);
}
}
}
int occ[nmax];
void fill(signed L, signed R, signed D) {
++L;
++R;
vector<int> p;
for(int i = L; i <= R; i++) {
occ[i] = 0;
if((i == L || v[i] < v[i - 1]) && (i == R || v[i] < v[i + 1])) p.emplace_back(i), occ[i] = 1;
}
DSU::init(0, sz(p));
set<pii> heap;
set<int> indemnizatii;
for(int i = 0; i < sz(p) - 1; i++) {
indemnizatii.emplace(i);
indemnizatii.emplace(i + 1);
int mx = v[p[i] + 1];
for(int j = p[i] + 2; j < p[i + 1]; j++)
mx = max(mx, v[j]);
DSU::mxR[i] = mx;
heap.emplace(mx - max(v[p[i]], v[p[i + 1]]), i);
}
auto get = [&](int p_) { return pii{DSU::coef(p_, p), p_}; };
while(!heap.empty() && heap.begin() -> first < D) {
auto [C, i] = *heap.begin();
heap.erase(heap.begin());
i = DSU::f(i);
int urm = DSU::nxt[i];
if(i != *indemnizatii.begin()) {
int ant = DSU::f(i - 1);
heap.erase(heap.find(get(ant)));
}
if(urm != *indemnizatii.rbegin())
heap.erase(heap.find(get(urm)));
if(v[p[i]] < v[p[urm]]) {
occ[p[urm]] = 0;
DSU::unite(i, urm);
indemnizatii.erase(urm);
if(i != *indemnizatii.begin()) {
int ant = DSU::f(i - 1);
heap.insert(get(ant));
}
if(i != *indemnizatii.rbegin())
heap.insert(get(i));
}
else {
occ[p[i]] = 0;
if(i != *indemnizatii.begin()) {
int ant = DSU::f(i - 1);
DSU::unite(ant, i);
heap.insert(get(ant));
}
if(urm != *indemnizatii.rbegin())
heap.insert(get(urm));
indemnizatii.erase(i);
}
}
}
void init(signed N, std::vector<signed> H) {
for(int i = 0; i < N; i++) v[i + 1] = H[i];
initglobals(0, N - 1);
}
signed max_towers(signed L, signed R, signed D) {
fill(L, R, D);
++L, ++R;
if([&]() {
for(int i = L; i <= R; i++)
if(timeout[i] != 0) return 0;
return 1;
}()) {
int mx = 0;
for(int i = L; i <= R; i++) mx = max(mx, v[i]);
return mx - max(v[L], v[R]) >= D? 2 : 1;
}
int l = L, r = R;
while (l <= r && timeout[l] < D) l++;
if(l > r) return 1;
int rez = 0;
if(L < l) {
int mn = L;
for(int i = L + 1; i < l; i++) if(dir[i] < L && timeout[i] != 0 && v[mn] > v[i]) mn = i;
int mx = 0;
for(int i = mn + 1; i < l; i++) mx = max(v[i], mx);
if(mx - max(v[l], v[mn]) >= D) rez++;
}
while(timeout[r] < D) r--;
if(r < R) {
int mn = R;
for(int i = r + 1; i < R; i++) if(dir[i] > R && timeout[i] != 0 && v[mn] > v[i]) mn = i;
int mx = 0;
for(int i = r + 1; i < mn; i++) mx = max(v[i], mx);
if(mx - max(v[r], v[mn]) >= D) rez++;
}
for(int i = l; i <= r; i++)
if(timeout[i] >= D) rez++;
return rez;
}
#undef int