#include "rect.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <stack>
typedef long long llong;
const int MAXLOG = 13;
const int MAXN = 2500 + 10;
const int INF = 1e8;
int n, m;
struct SparseMIN
{
int sparse[MAXLOG][MAXN];
int getLOG[MAXN];
int len;
void build(int a[], int length)
{
len = length;
for (int i = 1 ; i <= len ; ++i)
{
sparse[0][i] = a[i];
}
for (int lg = 1 ; (1 << lg) <= len ; ++lg)
{
for (int i = 1 ; i + (1 << lg) - 1 <= len ; ++i)
{
sparse[lg][i] = std::min(sparse[lg - 1][i], sparse[lg - 1][i + (1 << lg - 1)]);
}
}
for (int i = 1 ; i <= len ; ++i)
{
getLOG[i] = getLOG[i - 1];
if ((1 << getLOG[i] + 1) < i) getLOG[i]++;
}
}
int findMIN(int l, int r)
{
assert(r - l + 1 <= len);
int lg = getLOG[r - l + 1];
return std::min(sparse[lg][l], sparse[lg][r - (1 << lg) + 1]);
}
};
struct SparseMAX
{
int sparse[MAXLOG][MAXN];
int getLOG[MAXN];
int len;
void build(int a[], int length)
{
len = length;
for (int i = 1 ; i <= len ; ++i)
{
sparse[0][i] = a[i];
}
for (int lg = 1 ; (1 << lg) <= len ; ++lg)
{
for (int i = 1 ; i + (1 << lg) - 1 <= len ; ++i)
{
sparse[lg][i] = std::max(sparse[lg - 1][i], sparse[lg - 1][i + (1 << lg - 1)]);
}
}
for (int i = 1 ; i <= len ; ++i)
{
getLOG[i] = getLOG[i - 1];
if ((1 << getLOG[i] + 1) < i) getLOG[i]++;
}
}
int findMAX(int l, int r)
{
assert(r - l + 1 <= len);
int lg = getLOG[r - l + 1];
return std::max(sparse[lg][l], sparse[lg][r - (1 << lg) + 1]);
}
};
int a[MAXN][MAXN]; // >
int b[MAXN][MAXN]; // v
int c[MAXN][MAXN]; // <
int d[MAXN][MAXN]; // ^
int t[MAXN][MAXN];
int cpy[MAXN];
SparseMIN sparseRD[MAXN];
SparseMAX sparseRU[MAXN];
SparseMIN sparseCL[MAXN];
SparseMAX sparseCR[MAXN];
std::vector <int> possibleColE[MAXN][MAXN];
std::vector <int> possibleRowE[MAXN][MAXN];
bool isOK(int rowB, int colB, int rowE, int colE)
{
rowB--; colB--; rowE++; colE++;
if (sparseRD[rowB].findMIN(colB + 1, colE - 1) < rowE) return false;
if (sparseRU[rowE].findMAX(colB + 1, colE - 1) > rowB) return false;
if (sparseCL[colB].findMIN(rowB + 1, rowE - 1) < colE) return false;
if (sparseCR[colE].findMAX(rowB + 1, rowE - 1) > colB) return false;
return true;
}
llong count_rectangles(std::vector <std::vector<int>> _a)
{
n = _a.size(); m = _a[0].size();
for (int i = 0 ; i < n ; ++i)
{
for (int j = 0 ; j < m ; ++j)
{
t[i + 1][j + 1] = _a[i][j];
}
}
for (int i = 0 ; i <= n + 1 ; ++i)
{
t[i][0] = t[i][m + 1] = INF;
}
for (int i = 0 ; i <= m + 1 ; ++i)
{
t[0][i] = t[n + 1][i] = INF;
}
std::stack <int> st;
for (int i = 1 ; i <= n ; ++i)
{
while (st.size()) st.pop(); st.push(m + 1);
for (int j = m ; j >= 1 ; --j)
{
while (t[i][j] > t[i][st.top()])
{
st.pop();
}
a[i][j] = st.top();
st.push(j);
}
while (st.size()) st.pop(); st.push(0);
for (int j = 1 ; j <= m ; ++j)
{
while (t[i][j] > t[i][st.top()])
{
st.pop();
}
c[i][j] = st.top();
st.push(j);
}
}
for (int i = 1 ; i <= m ; ++i)
{
while (st.size()) st.pop(); st.push(n + 1);
for (int j = n ; j >= 1 ; --j)
{
while (t[j][i] > t[st.top()][i])
{
st.pop();
}
b[j][i] = st.top();
st.push(j);
}
while (st.size()) st.pop(); st.push(0);
for (int j = 1 ; j <= n ; ++j)
{
while (t[j][i] > t[st.top()][i])
{
st.pop();
}
d[j][i] = st.top();
st.push(j);
}
}
for (int i = 1 ; i <= n ; ++i)
{
sparseRD[i].build(b[i], m);
sparseRU[i].build(d[i], m);
}
for (int i = 1 ; i <= m ; ++i)
{
for (int j = 1 ; j <= n ; ++j)
{
cpy[j] = a[j][i];
}
sparseCL[i].build(cpy, n);
for (int j = 1 ; j <= n ; ++j)
{
cpy[j] = c[j][i];
}
sparseCR[i].build(cpy, n);
}
for (int i = 2 ; i <= n ; ++i)
{
for (int j = 2 ; j <= m ; ++j)
{
if (d[i][j] != 0) possibleRowE[d[i][j] + 1][j].push_back(i - 1);
if (c[i][j] != 0) possibleColE[i][c[i][j] + 1].push_back(j - 1);
}
}
for (int i = 2 ; i <= n ; ++i)
{
for (int j = 2 ; j <= m ; ++j)
{
if (possibleRowE[i][j].empty() || possibleRowE[i][j].back() != b[i - 1][j]) possibleRowE[i][j].push_back(b[i - 1][j]);
if (possibleColE[i][j].empty() || possibleColE[i][j].back() != a[i][j - 1]) possibleColE[i][j].push_back(a[i][j - 1]);
}
}
int answer = 0;
for (int rowB = 2 ; rowB < n ; ++rowB)
{
for (int colB = 2 ; colB < m ; ++colB)
{
for (const int &rowE : possibleRowE[rowB][colB])
{
for (const int &colE : possibleColE[rowB][colB])
{
answer += isOK(rowB, colB, rowE, colE);
}
}
}
}
return answer;
}
Compilation message
rect.cpp: In member function 'void SparseMIN::build(int*, int)':
rect.cpp:33:89: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
33 | sparse[lg][i] = std::min(sparse[lg - 1][i], sparse[lg - 1][i + (1 << lg - 1)]);
| ~~~^~~
rect.cpp:40:33: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
40 | if ((1 << getLOG[i] + 1) < i) getLOG[i]++;
| ~~~~~~~~~~^~~
rect.cpp: In member function 'void SparseMAX::build(int*, int)':
rect.cpp:70:89: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
70 | sparse[lg][i] = std::max(sparse[lg - 1][i], sparse[lg - 1][i + (1 << lg - 1)]);
| ~~~^~~
rect.cpp:77:33: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
77 | if ((1 << getLOG[i] + 1) < i) getLOG[i]++;
| ~~~~~~~~~~^~~
rect.cpp: In function 'llong count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:137:9: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
137 | while (st.size()) st.pop(); st.push(m + 1);
| ^~~~~
rect.cpp:137:37: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'while'
137 | while (st.size()) st.pop(); st.push(m + 1);
| ^~
rect.cpp:149:9: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
149 | while (st.size()) st.pop(); st.push(0);
| ^~~~~
rect.cpp:149:37: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'while'
149 | while (st.size()) st.pop(); st.push(0);
| ^~
rect.cpp:164:9: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
164 | while (st.size()) st.pop(); st.push(n + 1);
| ^~~~~
rect.cpp:164:37: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'while'
164 | while (st.size()) st.pop(); st.push(n + 1);
| ^~
rect.cpp:176:9: warning: this 'while' clause does not guard... [-Wmisleading-indentation]
176 | while (st.size()) st.pop(); st.push(0);
| ^~~~~
rect.cpp:176:37: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'while'
176 | while (st.size()) st.pop(); st.push(0);
| ^~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
104 ms |
296788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
104 ms |
296788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
104 ms |
296788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
104 ms |
296788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
130 ms |
359000 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
105 ms |
297300 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
104 ms |
296788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
