View difference between Paste ID: hZnGnSeZ and irGwcG5r

 #include <bits/stdc++.h>
 using namespace std;
 #define cin(vec) for(auto& i : vec) cin >> i
 #define cin_2d(vec, n, m) for(int i=0; i<n; i++) for(int j=0; j<m && cin >> vec[i][j]; j++);
 #define cout(vec) for(auto& i : vec) cout << i << " "; cout << "\n";
 #define cout_2d(vec, r, c) for(int i=0; i<r; i++, cout << "\n") for(int j=0; j<c && cout << vec[i][j] << " "; j++);
 #define cout_map(mp) for(auto& [f, s] : mp) cout << f << " : " << s << "\n"
 #define matrix(grid, n, m) vector < vector <ll> > grid(n, vector <ll> (m));
 #define Time cerr << "Time Taken: " << (float)clock() / CLOCKS_PER_SEC << " Secs" << "\n";
 #define ceil(n, m) (((n) / (m)) + ((n) % (m) ? 1 : 0))
 #define fixed(n) cout << fixed << setprecision(n)
 #define Num_of_Digits(n) ((int)log10(n)+1)
 #define getline(s) getline(cin >> ws, s)
 #define to_decimal(bin) stoi(bin, nullptr, 2)
 #define TC int t; cin >> t; while(t--)
 #define rall(s) s.rbegin(), s.rend()
 #define all(s) s.begin(), s.end()
 #define sz(x) int(x.size())
 #define Pair pair <int, int>
 #define fi first
 #define se second
 #define pb(x) push_back(x)
 #define ll long long
 #define PI acos(-1)
 #define Mod 1'000'000'007
 #define INF 2'000'000'000
 #define EPS 1e-9
 
 void Anwar_Rizk(){
   ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
   #ifndef ONLINE_JUDGE    // Anwar Rizk 🥇🖤
     freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
   #endif
   Time
 }
 
 int n, m;
 vector < vector <int> > grid;
 
 bool isValid(int r, int c){
   return r >= 0 && r < n && c >= 0 && c < m;
 }
 
 ll count(int i, int j){
   if(!isValid(i, j) || grid[i][j] == 0)  return 0;
   if(i == n - 1 && j == m - 1) return 1;
-  return count(i + 1, j) + count(i, j + 1) + count(i - 1, j) + count(i, j - 1);
+  grid[i][j] = 0;
   ll ans = count(i + 1, j) + count(i, j + 1) + count(i - 1, j) + count(i, j - 1);
   grid[i][j] = 1;
   return ans;
 }
 
 int main()
 {   Anwar_Rizk();
 
     cin >> n >> m;
     grid.resize(n, vector <int> (m));
     cin_2d(grid, n, m);
     cout << count(0, 0);
 
   return 0;
 }