CSES-solutions/CSES Problem Set/Counting Tilings.cpp
Segcolt 3f1e7cc8f3 Add another problem
I AM AN IDIOT! This kept giving TLE, turns out that I forgot to put the
dp itself to work!
2025-02-11 17:49:50 -03:00

130 lines
2.4 KiB
C++

/* 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';
}