994. Rotting Oranges.js

/**
 * @param {number[][]} grid
 * @return {number}
 */
var orangesRotting = function (grid) {
	let totalOranges = 0,
		rottenOranges = 0,
		elapsedMinutes = 0,
		width = grid[0].length,
		height = grid.length;
	const orangesToScan = [];

	for (let i = 0; i < grid.length; i++) {
		for (let j = 0; j < grid[0].length; j++) {
			if (grid[i][j] == 2) {
				orangesToScan.push([i, j]);
				rottenOranges++;
				totalOranges++;
			}
			if (grid[i][j] == 1) {
				totalOranges++;
			}
		}
	}

	if (rottenOranges == totalOranges) return elapsedMinutes;

	while (orangesToScan.length && rottenOranges < totalOranges) {
		let lookForAdjacentOranges = orangesToScan.splice(0, orangesToScan.length);
		while (lookForAdjacentOranges.length) {
			let [row, col] = lookForAdjacentOranges.pop();
			// up
			if (row > 0 && grid[row - 1][col] == 1) {
				grid[row - 1][col] = 2;
				rottenOranges++;
				orangesToScan.push([row - 1, col]);
			}
			// down
			if (row < height - 1 && grid[row + 1][col] == 1) {
				grid[row + 1][col] = 2;
				rottenOranges++;
				orangesToScan.push([row + 1, col]);
			}
			// left
			if (col > 0 && grid[row][col - 1] == 1) {
				grid[row][col - 1] = 2;
				rottenOranges++;
				orangesToScan.push([row, col - 1]);
			}
			// right
			if (col < width - 1 && grid[row][col + 1] == 1) {
				grid[row][col + 1] = 2;
				rottenOranges++;
				orangesToScan.push([row, col + 1]);
			}
		}
		elapsedMinutes++;
	}

	return (rottenOranges == totalOranges) ? elapsedMinutes : -1;
};