Submission #328772

#	Time	Username	Problem	Language	Result	Execution time	Memory
328772		VROOM_VARUN	Rectangles (IOI19_rect)	C++14	100 / 100	2032 ms	371380 KiB

rect

// /*
// ID: varunra2
// LANG: C++
// TASK: rectangles
// */

// #include <bits/stdc++.h>
// using namespace std;

// #ifdef DEBUG
// #include "lib/debug.h"
// #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
// #define debug_arr(...) \
//   cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
// #pragma GCC diagnostic ignored "-Wsign-compare"
// //#pragma GCC diagnostic ignored "-Wunused-parameter"
// //#pragma GCC diagnostic ignored "-Wunused-variable"
// #else
// #define debug(...) 42
// #endif

// #define EPS 1e-9
// #define IN(A, B, C) assert(B <= A && A <= C)
// #define INF (int)1e9
// #define MEM(a, b) memset(a, (b), sizeof(a))
// #define MOD 1000000007
// #define MP make_pair
// #define PB push_back
// #define all(cont) cont.begin(), cont.end()
// #define rall(cont) cont.end(), cont.begin()
// #define x first
// #define y second

// const double PI = acos(-1.0);
// typedef long long ll;
// typedef long double ld;
// typedef pair<int, int> PII;
// typedef map<int, int> MPII;
// typedef multiset<int> MSETI;
// typedef set<int> SETI;
// typedef set<string> SETS;
// typedef vector<int> VI;
// typedef vector<PII> VII;
// typedef vector<VI> VVI;
// typedef vector<string> VS;

// #define rep(i, a, b) for (int i = a; i < (b); ++i)
// #define trav(a, x) for (auto& a : x)
// #define sz(x) (int)(x).size()
// typedef pair<int, int> pii;
// typedef vector<int> vi;
// #pragma GCC diagnostic ignored "-Wsign-compare"
// util functions

// bool f(int a, VI b) { return a >= *min_element(all(b)); }

// bool ok(VVI vals) {
//   if (sz(vals) < 3) return false;
//   if (sz(vals[0]) < 3) return false;
//   int n = sz(vals);
//   int m = sz(vals[0]);
//   for (int i = 1; i < n - 1; i++) {
//     for (int j = 1; j < m - 1; j++) {
//       int val = vals[i][j];
//       int v1 = vals[0][j];
//       int v2 = vals[n - 1][j];
//       int v3 = vals[i][0];
//       int v4 = vals[i][m - 1];
//       if (f(val, {v1, v2, v3, v4})) return false;
//     }
//   }
//   return true;
// }

// VVI get(VVI& vals, int l, int r, int s, int e) {
//   VVI ret(e - s + 1, VI(r - l + 1));
//   for (int i = s; i <= e; i++) {
//     for (int j = l; j <= r; j++) {
//       ret[i - s][j - l] = vals[i][j];
//     }
//   }
//   return ret;
// }

// ll count_rectangles(VVI vals) {
//   int ret = 0;
//   int bad = 0;
//   for (int i = 0; i < sz(vals); i++) {
//     for (int j = 0; j < sz(vals[0]); j++) {
//       for (int k = i; k < sz(vals); k++) {
//         for (int l = j; l < sz(vals[0]); l++) {
//           int cur = ok(get(vals, j, l, i, k));
//           if (cur)
//             ret++;
//           else
//             bad++;
//           // if (cur) debug(i, j, k, l);
//         }
//       }
//     }
//   }
//   return ret;
// }

// model_solution/rect-mruxim-n2lg.cpp
 
// ... ... .. ....!
// ... ....... .... ...!
 
#include<bits/stdc++.h>
using namespace std;
 
#define rep(i, n) for(int i = 0, i##__n = (int)(n); i < i##__n; ++i)
#define fer(i, a, b) for(int i = (int)(a), i##__b = (int)(b); i < i##__b; ++i)
#define rof(i, b, a) for(int i = (int)(b), i##__a = (int)(a); i-- > i##__a; )
#define sz(x) (int((x).size()))
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define X first
#define Y second
//#define endl '\n'
 
template<class P, class Q> inline void smin(P &a, Q b) { if (b < a) a = b; }
template<class P, class Q> inline void smax(P &a, Q b) { if (a < b) a = b; }
 
typedef long long ll;
typedef pair<int, int> pii;
 
////////////////////////////////////////////////////////////////////////////////
 
const int maxn = 3000 + 10;
 
 
int n, m;
vector<vector<int>> H;
 
short L[maxn][maxn], R[maxn][maxn], U[maxn][maxn], D[maxn][maxn];
short UL[maxn][maxn], DL[maxn][maxn], LU[maxn][maxn], RU[maxn][maxn];
 
vector<ll> v;
 
void precalc() {
	short st[maxn];
	
	rep(i, n) {
		int t = 0;
		rep(j, m) {
			while(t && H[i][j] > H[i][st[t-1]]) t--;
			L[i][j] = (t ? st[t-1] : -1);
			st[t++] = j;
		}
	}
	rep(i, n) {
		int t = 0;
		rof(j, m, 0) {
			while(t && H[i][j] > H[i][st[t-1]]) t--;
			R[i][j] = (t ? st[t-1] : -1);
			st[t++] = j;
		}
	}
	rep(j, m) {
		int t = 0;
		rep(i, n) {
			while(t && H[i][j] > H[st[t-1]][j]) t--;
			U[i][j] = (t ? st[t-1] : -1);
			st[t++] = i;
		}
	}
	rep(j, m) {
		int t = 0;
		rof(i, n, 0) {
			while(t && H[i][j] > H[st[t-1]][j]) t--;
			D[i][j] = (t ? st[t-1] : -1);
			st[t++] = i;
		}
	}
 
	rep(j, m) rep(i, n) {
		if(U[i][j] != -1) {
			if(j > 0 && U[i][j] == U[i][j-1]) UL[i][j] = UL[i][j-1];
			else if(j > 0 && i == D[U[i][j]][j-1]) UL[i][j] = DL[U[i][j]][j-1];
			else UL[i][j] = j;
		}
		if(D[i][j] != -1) {
			if(j > 0 && D[i][j] == D[i][j-1]) DL[i][j] = DL[i][j-1];
			else if(j > 0 && i == U[D[i][j]][j-1]) DL[i][j] = UL[D[i][j]][j-1];
			else DL[i][j] = j;
		}
	}
 
	rep(i, n) rep(j, m) {
		if(L[i][j] != -1) {
			if(i > 0 && L[i][j] == L[i-1][j]) LU[i][j] = LU[i-1][j];
			else if(i > 0 && j == R[i-1][L[i][j]]) LU[i][j] = RU[i-1][L[i][j]];
			else LU[i][j] = i;
		}
		if(R[i][j] != -1) {
			if(i > 0 && R[i][j] == R[i-1][j]) RU[i][j] = RU[i-1][j];
			else if(i > 0 && j == L[i-1][R[i][j]]) RU[i][j] = LU[i-1][R[i][j]];
			else RU[i][j] = i;
		}
	}
}
 
void check(int i1, int i2, int j1, int j2) {
	if(i2 < i1 || j2 < j1) return;
	if(!((R[i2][j1-1]-1 == j2 && RU[i2][j1-1] <= i1) || (L[i2][j2+1]+1 == j1 && LU[i2][j2+1] <= i1))) return;
	if(!((D[i1-1][j2]-1 == i2 && DL[i1-1][j2] <= j1) || (U[i2+1][j2]+1 == i1 && UL[i2+1][j2] <= j1))) return;
	v.pb((((ll)i1 * maxn + i2) * maxn + j1) * maxn + j2);
}
 
int count_rectangles(vector<vector<int>> _H) {
	H = _H;
	n = sz(H);
	m = sz(H[0]);
 
	precalc();
 
	fer(i, 1, n-1) fer(j, 1, m-1) {
		if(U[i+1][j] != -1 && L[i][j+1] != -1) check(U[i+1][j]+1, i, L[i][j+1]+1, j);
		if(U[i+1][j] != -1 && R[i][j-1] != -1) check(U[i+1][j]+1, i, j, R[i][j-1]-1);
		if(D[i-1][j] != -1 && L[i][j+1] != -1) check(i, D[i-1][j]-1, L[i][j+1]+1, j);
		if(D[i-1][j] != -1 && R[i][j-1] != -1) check(i, D[i-1][j]-1, j, R[i][j-1]-1);
		if(D[i-1][j] != -1 && R[D[i-1][j]-1][j-1] != -1) check(i, D[i-1][j]-1, j, R[D[i-1][j]-1][j-1]-1);
		if(D[i-1][j] != -1 && L[D[i-1][j]-1][j+1] != -1) check(i, D[i-1][j]-1, L[D[i-1][j]-1][j+1]+1, j);
	}
	
	sort(all(v));
	v.resize(unique(all(v)) - v.begin());
 
	return sz(v);
}

Compilation message (stderr)

rect.cpp:13:1: warning: multi-line comment [-Wcomment]
   13 | // #define debug_arr(...) \
      | ^

• Subtask 1: 8 / 8
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 22 / 22
• Subtask 5: 10 / 10
• Subtask 6: 13 / 13
• Subtask 7: 28 / 28