| 3 | |
| 4 | |
| 5 | void dfs(int i , int j, vector<vector<char>> &arr, vector<vector<int>> &vis){ //function for DFS |
| 6 | |
| 7 | vis[i][j]=1; // mark island as visited |
| 8 | |
| 9 | int dx[]={0,0,1,-1}; // array for changing values of x |
| 10 | int dy[]={-1,1,0,0}; // array for changing values of y |
| 11 | |
| 12 | for(int k=0;k<4;k++){ |
| 13 | if(i+dx[k]<arr.size() && i+dx[k]>=0 && j+dy[k]<arr[0].size() && j+dy[k]>=0 && arr[i+dx[k]][j+dy[k]]=='1' && vis[i+dx[k]][j+dy[k]]==0){ // if index (i+dx,j+dy) is in bounds of the grid, value at that index is 1 and index is not visited, mark it as visited and then perform DFS on it |
| 14 | vis[i+dx[k]][j+dy[k]]=1; |
| 15 | dfs(i+dx[k],j+dy[k],arr,vis); |
| 16 | } |
| 17 | } |
| 18 | |
| 19 | } |
| 20 | |
| 21 | |
| 22 | int numIslands(vector<vector<char>>& grid) { |