What's a good algorithm to generate a maze?

Question

Say you want a simple maze on an N by M grid, with one path through, and a good number of dead ends, but that looks \"right\" (i.e. like someone made it by hand without too

Answer 1

Recursive Backtracking is the easiest algorithm to implement.

Here's a Java implementation:

Here Cell is a class representing a cell in a 2D grid and cells is a 2D array of Cell objects. Cell has boolean variables top, bottom, left and right to indicate whether a cell has walls on these sides, a boolean variable visited to check whether we have traversed it and two integer variables row and col to indicate its position in the grid.

Cell current = cells[0][0] , next;
    current.visited=true;
    do{
        next = getNeighbour(current);
        if(next!=null){
            removeWall(current , next);
            st.push(current);
            current = next;
            current.visited = true;
        }
        else {
            current = st.pop();
        }
    }
    while (!st.empty());


    private Cell getNeighbour(Cell cell){
    ArrayList ara = new ArrayList<>();
    if(cell.col>0 && !cells[cell.col-1][cell.row].visited)
         ara.add(cells[cell.col-1][cell.row]);

    if(cell.row>0 && !cells[cell.col][cell.row-1].visited)
         ara.add(cells[cell.col][cell.row-1]);

    if(cell.col0){
        return ara.get(new Random().nextInt(ara.size()));
    }else{
        return null;
    }
}
private void removeWall(Cell curr , Cell nxt){
    if((curr.col == nxt.col) && (curr.row == nxt.row+1)){/// top
        curr.top=nxt.botttom=false;
    }
    if(curr.col==nxt.col && curr.row == nxt.row-1){///bottom
        curr.botttom = nxt.top = false;
    }
    if(curr.col==nxt.col-1 && curr.row==nxt.row ){///right
        curr.right = nxt.left = false;
    }
    if(curr.col == nxt.col+1 && curr.row == nxt.row){///left
        curr.left = nxt.right = false;
    }
}