Pathfinding

From GPWiki

If you create a game with pathfinding(RTS game, Adventure, RPG or sometimes boardgames), then you need to know a algorithm.
Pathfinding algorithms are different: If you make a game with tiles you can use a accurate algorithm what can examine all tiles. But a continous game environment need a quicklier algorithm. Here is the A* algorithm, remember don't grow angry if it doesn't work. It's pseudo code you know.
I've converted this code to qbasic and it works (in a textbased environment with a size of 80x50 tiles, but very quick.)

class PSEUDO_CODE_PATHFINDING_IN*A
{
int list(XSiz,YSiz)   ;Declare the tile-list contains the information, if a tile is open,closed,or not examined.
int fromX,fromY(XSiz,YSiz); array that stores the parent tile position of the current tile in it
int Yx,Yy                  ;Your position
int Tx,Ty                  ;Targets position
int map(XSiz,YSiz);Declare the map-array contains information about the map (unpassable,open terrain etc.)
int pathx(length_path)
int pathy(length_path)
repeat 
 for(x 1 to XSiz)
  for(y 1 to YSiz)
    if  list x ,y is open then 
      check all adjacent tiles
        if adjacent tile is not examined and map x,y is open too then that tile is open
        set the position of the parent_tile in array fromXY
     if xy = txy then end the loop
  next y
 next x
until Target_pos_reached
 
function createpath(x1,y1,x2,y2)
repeat 
 pathx(count)=x
 pathy(count)=y
 x2=fromx(x2,y2)
 y2=fromy(x2,y2)
 count++
until x=x2,y=y2
 
}

Tadaa! Here is your path, if it is converted correctly.,