#codingexercise
Given a room and a robot that can move in one of four directions, find the size of the room. 
Int GetSize(int x, int y) // current co-ordinate of GetSize 
{ 
// if one of the directions faces the wall, use it as the start 
// else walk in one of four directions that is available 
// or start from top-left and start the walk along the boundary of the room 
// noting the four corners 
// use it to calculate width and length 
Int wallstartx=INT_MIN; 
Int wallstarty=INT_MIN; 
int i = x;
int j = y;
//start at top left
For (; Move(i,j,0);I--);
Wallstartx=i; 
Wallstarty=j; 
If (wallstartx==INT_MIN || wallstarty==INT_MIN) 
{ 
    Int I = x; 
    Int j = y; 
   // move left to wall
   While(Move(i,j,0) == true)) 
            i--; 
    Wallstartx = i; 
    Wallstarty =j; 
} 
// we have a position on the wall, now we run along the boundary 
I = wallstartx; 
For (int j=wallstarty; Move(I, j,1); j++); 
Int topleftx=I; 
Int toplefty = j; 
For (int i=wallstartx; Move(I, j,2); i++); 
Int toprightx=I; 
Int toprighty = j; 
For (int j=toprighty; Move(I, j,3); j--); 
Int bottomrightx=I; 
Int bottomrighty=j; 
For (int i=bottomrightx; Move(I, j,0); I--); 
Int bottomleft=I; 
Int bottomleft = j; 
For (int j = bottomlefty; Move(I,j,1) && I != wallstartx && j != wallstarty; j--); 
Assert(wallstartx == I && wallstarty == j); 
Int width = Math.Abs(bottomrightx-bottomleftx); 
Int height = Math.Abs(toplefty-bottomlefty); 
Return width*height; 
} 

If the room was irregular and not a rectangle, we would cover each coordinate horizontally and count each postion occupied as a unit square,  when we cover all the squares in one row, we proceed to the next. In this case, we could always try to begin from top left.