C++ Minesweeper checking adjacent squares and adding hints [closed] - c++

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So, I have a pretty good idea of how to implement the majority of the program. However, I am having a hard time coming up with an algorithm to add the hints of array locations adjacent to mines. The real trouble I am seeing is that the edge cases almost make it like you have two functions to deal with it (I have 20 line max on all functions). I know that from the position of the mine we want a loop to check row - 1 to row +1 and col -1 to col +1, but is it possible to do this in one function with the code I have for the game? If so, some advice would be great!
EDIT!
SO I think I have come up with the algorithm that works for all cases, but it is outputting bad info. I am pretty sure it is due to improper casting, but I am unable to see what's wrong.
Here are the two functions I wrote to add the hints:
void add_hints_chk(char ** game_board, int cur_row, int cur_col, int
rows, int cols)
{
int row_start = 0, row_end = 0, col_start = 0, col_end = 0;
if (cur_row - 1 < 0)
{
//Top edge case
row_start = 0;
}
else
{
row_start = cur_row - 1;
}
if (cur_row + 1 > rows - 1)
{
//bottom edge case
row_end = rows - 1;
}
else
{
row_end = cur_row + 1;
}
if (cur_col - 1 < 0)
{
//Left edge case
col_start = 0;
}
else
{
col_start = cur_col - 1;
}
if (cur_col - 1 > cols - 1)
{
//Right edge case
col_end = cols - 1;
}
else
{
col_end = cur_col + 1;
}
add_hints(game_board, row_start, row_end, col_start, col_end);
}
void add_hints(char **board, int row_start, int row_end, int col_start,
int col_end)
{
int tmp_int = 0;
for (int i = row_start; i <= row_end; i++)
{
for (int j = col_start; j <= col_end; j++)
{
if (board[i][j] != '*')
{
if (board[i][j] == ' ')
{
tmp_int = 1;
board[i][j] = (char)tmp_int;
}
else
{
tmp_int = (int)board[i][j];
tmp_int++;
board[i][j] += (char)tmp_int;
}
}
}
}
}
So, when I print the array, I get the little box with a q-mark in it. Am I converting tmp_int back to a char incorrectly?

Answer 1

There are different strategies to handle this. One simple strategy is creating a larger grid (add one line on each side) that is initialized with no bombs; make the board a view that hides the borders. With this strategy you know that you can step out of the game board without causing issues (since the data structure has an additional row).
Alternatively you can test whether the coordinates are within the valid range before calling the function that tests, or as the first step within that function.
Also you can consider precalculating the values for all of the map, whenever you add a bomb to the board during the pre-game phase, increment the counter of bombs in the vicinity for all of the surrounding positions. You can use either of the above approaches to handle the border conditions.

Answer 2

For any cell, C, there are 8 possible locations to check:
# # #
# C #
# # #
Before extracting data from the array, each outer location must be boundary checked.
You may be able to generalize, for example, if the value (column - 1) is out of bounds, you don't need to check 3 locations.
In your case, I would go with the brute force method and check each outer cell for boundary before accessing it. If profiling identifies this as the primary bottleneck, the come back and optimize it. Otherwise move on.
Edit 1: Being blunt
int C_left = C_column - 1;
int C_right = C_column + 1;
if (C_left >= 0)
{
// The left column can be accessed.
}
if (C_right < MAXIMUM_COLUMNS)
{
// The right columns can be accessed.
}
// Similarly for the rows.