From 3f1e7cc8f30081bd32ae04af740c7932f955dafb Mon Sep 17 00:00:00 2001
From: Segcolt <9hmbzr275@mozmail.com>
Date: Tue, 11 Feb 2025 17:49:50 -0300
Subject: [PATCH] Add another problem

I AM AN IDIOT! This kept giving TLE, turns out that I forgot to put the
dp itself to work!
---
 CSES Problem Set/Counting Tilings.cpp | 129 ++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 CSES Problem Set/Counting Tilings.cpp

diff --git a/CSES Problem Set/Counting Tilings.cpp b/CSES Problem Set/Counting Tilings.cpp
new file mode 100644
index 0000000..f829690
--- /dev/null
+++ b/CSES Problem Set/Counting Tilings.cpp	
@@ -0,0 +1,129 @@
+/* Problem URL: https://cses.fi/problemset/task/2181 */
+ 
+#include <bits/stdc++.h>
+ 
+using namespace std;
+ 
+#define V vector
+ 
+#define rmin(a, b) a = min(a, b)
+#define rmax(a, b) a = max(a, b)
+ 
+#define rep(i, lim) for (size_t i = 0; i < (lim); i++)
+#define nrep(i, s, lim) for (size_t i = s; i < (lim); i++)
+ 
+#define repv(i, v) for (auto &i : (v))
+#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
+#define sortv(v) sort(v.begin(), v.end())
+#define all(v) (v).begin(), (v).end()
+ 
+using vi = vector<int>;
+using vvi = vector<vi>;
+using vvvi = vector<vvi>;
+using vvvvi = vector<vvvi>;
+ 
+using ll = long long;
+ 
+using vl = vector<ll>;
+using vvl = vector<vl>;
+using vvvl = vector<vvl>;
+using vvvvl = vector<vvvl>;
+ 
+template<class v>
+auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
+    os << vec[0];
+    for (size_t i = 1; i < vec.size(); i++) {
+        os << ' ' << vec[i];
+    }
+    os << '\n';
+    return os;
+}
+ 
+template<class v>
+auto operator>>(istream &is, vector<v> &vec)->istream& {
+    for (auto &i : vec) {
+        is >> i;
+    }
+    return is;
+}
+ 
+template<class v>
+auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
+    for (auto &i : vec) {
+        os << i[0];
+        for (size_t j = 1; j < i.size(); j++) {
+            os << ' ' << i[j];
+        }
+        os << '\n';
+    }
+    return os;
+}
+ 
+template<class v>
+auto operator>>(istream  &is, vector<vector<v>> &vec)->istream& {
+    for (auto &i : vec) {
+        for (auto &j : i) {
+            is >> j;
+        }
+    }
+    return is;
+}
+ 
+int n, m;
+ll mod = 1e9 + 7;
+ 
+namespace { vvl memo; }
+ 
+ll dp(int i, int mask)
+{
+    if (i == m) {
+        return mask == 0 ? 1 : 0;
+    }
+ 
+    ll &ans = memo[i][mask];
+    if (ans != -1) {
+        return ans;
+    }
+ 
+    ans = 0;
+    rep(j, 1 << n) {
+        if (mask & j) {
+            continue;
+        }
+ 
+        int test = ~(mask | j);
+ 
+        int count = 0;
+        rep(k, n) {
+            if ((test >> k) & 1) {
+                count++;
+            } else {
+                if (count & 1) {
+                    break;
+                }
+                count = 0;
+            }
+        }
+ 
+        if (count & 1) {
+            continue;
+        }
+ 
+        ans = (ans + dp(i + 1, j)) % mod;
+    }
+ 
+    return ans;
+}
+    
+ 
+int main()
+{
+    ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+ 
+    cin >> n >> m;
+ 
+    memo.assign(m, vl((1 << (n + 1)), -1));
+ 
+    cout << dp(0, 0) << '\n';
+}