Question

can you please convert this python code into java?

Python code is as shown below:

# recursive function
def row_puzzle_rec(row, pos, visited):
   # if the element at the current position is 0 we have reached our goal
   if row[pos] == 0:
       possible = True
   else:
       # make a copy of the visited array
       visited = visited[:]
       # if the element at the current position has been already visited then it's a loop.
       # as then its not possible to reach the last element, set possible to False
       if visited[pos]:
           possible = False
       else:
           # set visitied for the element as True
           visited[pos] = True
           possible = False
           # if its possible to move left then recurse in the left direction
           if pos - row[pos] > 0 and row_puzzle_rec(row, pos - row[pos], visited):
               # return immediately if the goal is reached
               return True
           # if its possible to move right then recurse in the right direction
           if pos + row[pos] < len(row) and row_puzzle_rec(row, pos + row[pos], visited):
               # return immediately if the goal is reached.
               return True
   return possible

def row_puzzle(row):
   # visited array will be used to check if a particular element was visited
   # initialize the array to False
   visited = [False for item in range(len(row))]
   # second argument is the token position initialized to 0
   return row_puzzle_rec(row, 0, visited)

possible = row_puzzle([2, 4, 5, 3, 1, 3, 1, 4, 0])
print(possible)
possible = row_puzzle([1, 3, 2, 1, 3, 4, 0])
print(possible)

Answer 1

Java Code:

public class Main
{
    public static boolean row_puzzle_rec(int row[], int pos, boolean visited[]) {
        boolean possible;
        // if the element at the current position is 0 we have reached our goal
        if(row[pos]==0) {
            possible = true;
        }
        else {
            // make a copy of the visited array
            visited = visited;
            // if the element at the current position has been already visited then it's a loop.
            // as then its not possible to reach the last element, set possible to False
            if(visited[pos]) {
                possible = false;
            }
            else {
                // set visitied for the element as True
                visited[pos] = true;
                possible = false;
                // if its possible to move left then recurse in the left direction
                if(pos - row[pos] > 0 && row_puzzle_rec(row, pos - row[pos], visited)) { 
                    // return immediately if the goal is reached
                    return true;
                }
                // if its possible to move right then recurse in the right direction
                if(pos + row[pos] < row.length && row_puzzle_rec(row, pos + row[pos], visited)) {
                    // return immediately if the goal is reached.
                    return true;
                }
            }
        }
        return possible;
    }
        public static boolean row_puzzle(int row[]) {
            boolean visited[] = new boolean[row.length];
            // visited array will be used to check if a particular element was visited
        // initialize the array to False
            for(int i = 0; i < row.length; i++)
            visited[i] = false;
            // second argument is the token position initialized to 0
            return row_puzzle_rec(row, 0, visited);
        }
        
        public static void main(String[] args) {
                boolean possible;
                possible = row_puzzle(new int[]{2, 4, 5, 3, 1, 3, 1, 4, 0});
        System.out.println(possible);
        possible = row_puzzle(new int[]{1, 3, 2, 1, 3, 4, 0});
        System.out.println(possible);
        }
}

Output:

Please name the java file as Main.java