| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 373851 | ijxjdjd | Rectangles (IOI19_rect) | C++14 | 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 "rect.h"
#include <bits/stdc++.h>
#define f first
#define s second
const int MAXN = 85;
using ll = long long;
std::unordered_set<int> right[MAXN][MAXN];
std::unordered_set<int> down[MAXN][MAXN];
std::vector<std::pair<int, int>> rightP[MAXN][MAXN];
std::vector<std::pair<int, int>> downP[MAXN][MAXN];
std::vector<std::vector<int>> a;
int N, M;
void setPairs() {
for (int i = 0; i < N; i++) {
for (int j = 0; j < M; j++) {
for (int p : right[i][j]) {
int u = i;
while (right[u+1][j].count(p)) {
u++;
}
int lst = u;
rightP[i][j].push_back({lst, p});
// while (u >= i) {
// rightP[u][j].push_back({lst, p});
// if (u != i) {
// right[u][j].erase(p);
// }
// u--;
// }
}
}
}
for (int j = 0; j < M; j++) {
for (int i = 0; i < N; i++) {
for (int p : down[i][j]) {
int u = j;
while (down[i][u+1].count(p)) {
u++;
}
int lst = u;
downP[i][j].push_back({p, lst});
// while (u >= j) {
// downP[i][u].push_back({p, lst});
// if (u != j) {
// down[i][u].erase(p);
// }
// u--;
// }
}
}
}
}
void getIntervals() {
for (int i = 1; i < N-1; i++) {
std::stack<std::pair<int, int>> st;
st.push({a[i][0], 0});
for (int j = 1; j < M; j++) {
while (st.size() && a[i][j] > st.top().f) {
if (st.top().s + 1 <= j-1) {
right[i][st.top().s+1].insert(j-1);
}
st.pop();
}
if (st.size() && st.top().s + 1 <= j-1) {
right[i][st.top().s+1].insert(j-1);
}
st.push({a[i][j], j});
}
}
for (int j = 1; j < M-1; j++) {
std::stack<std::pair<int, int>> st;
st.push({a[0][j], 0});
for (int i = 1; i < N; i++) {
while (st.size() && a[i][j] > st.top().f) {
if (st.top().s + 1 <= i-1) {
down[st.top().s+1][j].insert(i-1);
}
st.pop();
}
if (st.size() && st.top().s + 1 <= i-1) {
down[st.top().s+1][j].insert(i-1);
}
st.push({a[i][j], i});
}
}
setPairs();
}
int fen[MAXN];
void add(int val, int id) {
for (;id<MAXN;id=(id|(id+1))) {
fen[id]+=val;
}
}
int sm(int r) {
int rs = 0;
for (;r >= 0; r=(r&(r+1)) - 1) {
rs += fen[r];
}
return rs;
}
int sm(int l, int r) {
return sm(r) - sm(l-1);
}
long long count_rectangles(std::vector<std::vector<int> > board) {
a = board;
N = a.size();
M = a[0].size();
if (N == 1 || M == 1) {
return 0;
}
getIntervals();
ll res = 0;
for (int i = 0; i < N; i++) {
for (int j = 0; j < M; j++) {
std::sort(rightP[i][j].begin(), rightP[i][j].end());
std::sort(downP[i][j].begin(), downP[i][j].end());
int u = 0;
for (auto& p : rightP[i][j]) {
while (u < downP[i][j].size() && downP[i][j][u].f <= p.f) {
add(1, downP[i][j][u].s);
u++;
}
res += sm(p.s, MAXN-1);
}
memset(fen, 0, sizeof(fen);)
// while (--u>= 0) {
// add(-1, downP[i][j][u].s);
// }
}
}
return res;
}