0994-rotting-oranges.ts

functionorangesRotting(grid: number[][]): number{
let[ROWS,COLS,time,fresh,q]=[grid.length,grid[0].length,0,0,[]];
letdirs=[
[0,1],
[0,-1],
[1,0],
[-1,0],
];

// count fresh oranges and add rotten oranges to queue
for(leti=0;i<ROWS;i++){
for(letj=0;j<COLS;j++){
if(grid[i][j]===1){
fresh++;
}
if(grid[i][j]===2){
q.push([i,j]);
}
}
}

while(q.length>0&&fresh>0){
letqLen=q.length;

for(letrot=0;rot<qLen;rot++){
let[row,col]=q.shift();

for(letdirofdirs){
let[r,c]=[row+dir[0],col+dir[1]];

if(
r<0||
r>=ROWS||
c<0||
c>=COLS||
grid[r][c]!==1
){
continue;
}

grid[r][c]=2;
fresh--;
q.push([r,c]);
}
}
time++;
}
returnfresh>0 ? -1 : time;
}