exctracting a list of simple shapes from an image-like data grid [closed]

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For a program I'm required to fill a bunch of variables relating to a grid. On the grid different chars represent different cars. Each car can be represented by 2 or 3 chars in a line (either vertical or horizontal).

/* Structure to hold information about a car */
typedef struct
{
    /* The location of the front of the car.  As all cars are assumed
       to be facing either north or west, this location represents
       the northwest segment of the car */
    LOCATION front;
    /* The orientation of the car */
    ORIENTATION orientation;
    /* The length of the car */
    int length;
} CARINFO;

I want to go through a for loop cycling through all the different cars (type CARINFO) and fill the variables such as length and front. I have all the logic for this for example:

if ((carpark.grid[i + 1][j] == car && carpark.grid[i - 1][j] == car) || // (left a开发者_如何学JAVAnd right) OR
    (carpark.grid[i][j + 1] == car && carpark.grid[i][j - 1] == car)) //    (up and down)
    CAR.length = 3;

I have used car as a char and CAR as a CARINFO.

If I had struct CARINFO a; how would I make car = a and do the same for all the other cars?

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I'm not going to provide you with code, but an idea. What you should do is, well first basically a loop on the rows, inside it a loop on the columns:

for (i = 0; i < grid_row_size; ++i)
    for (j = 0; j < grid_col_size; ++j)

Then you should detect a car (like the code you provided, but make sure you take care of boundaries. So for example when i==0 you shouldn't check grid[i-1][j].

Then, whenever you found a car, you set it's length, position and orientation they way you like and add it to a list (array) of CARINFO.

Finally, to make sure you don't find a car twice, whenever you find a car on the grid, you go over it and mark it as car_already_seen.