classSolution {

funwallsAndGates(rooms:Array<IntArray>):Unit {

val queue:Queue<Pair<Int,Int>>=LinkedList()

for (iin0 until rooms.size) {

for (jin0 until rooms[0].size) {

if (rooms[i][j]==0) {

queue.offer(Pair(i, j))

}

}

}

val directions= arrayOf(arrayOf(-1,0), arrayOf(1,0), arrayOf(0,-1), arrayOf(0,1))

var distance=1

while (queue.isNotEmpty()) {

val size= queue.size

repeat(size) {

val cell= queue.poll()

for (directionin directions) {

val newRow= cell.first+direction[0]

val newCol= cell.second+direction[1]

if (newRow>=0&& newRow< rooms.size&& newCol>=0&& newCol< rooms[0].size&& rooms[newRow][newCol]==Integer.MAX_VALUE) {

rooms[newRow][newCol]= distance

queue.offer(Pair(newRow, newCol))

}

}

}

distance++

}

}

}