Codeforces Round 871 (Div. 4) 1829E - The Lakes Solution

 Problem Link :  https://codeforces.com/contest/1829/problem/E

Solution in C++:

1. /// Author : AH_Tonmoy
2. #include <bits/stdc++.h>
3. using namespace std;
4. const int mx = 1e3+3 ;
5. int a[mx][mx] , vis[mx][mx] , ans , sum = 0 , n , m ;
6. vector<int> dx={+1,-1,0,0};
7. vector<int> dy={0,0,+1,-1};
8. void dfs ( int i , int j ) {
9. if ( i < 1 || i > n || j < 1 || j > m || vis[i][j] == 1 || a[i][j] == 0 )
10. return ;
11. sum += a[i][j] ;
12. vis[i][j] = 1 ;
13. for ( int ts = 0 ; ts < 4 ; ts++) {
14. dfs(i + dx[ts], j + dy[ts]);
15. }
16. }
17. int32_t main() {
18. ios_base::sync_with_stdio(0);
19. cin.tie(0);
20. int t;
21. cin >> t;
22. while (t--) {
23. cin >> n >> m ;
24. for ( int i = 1 ; i <= n ; i++) {
25. for ( int j = 1 ; j <= m ; j++){
26. cin >> a[i][j];
27. vis[i][j] = 0 ;
28. }
29. }
30. int ans = 0 ;
31. for ( int i = 1 ; i <= n ; i++) {
32. for ( int j = 1 ; j <= m ; j++){
33. sum = 0 ;
34. dfs(i , j ) ;
35. ans = max ( sum , ans ) ;
36. }
37. }
38. cout << ans <<"\n";
39. }
40. return 0 ;
41. }