* https://leetcode.com/problems/rotting-oranges/
* Time O(ROWS * COLS) | Space O(ROWS * COLS)
* @param {number[][]} grid
* @return {number}
*/
var orangesRotting = function (grid) {
const { queue, orangeCount } = searchGrid(grid);
const { rottenCount, minutes } = bfs(grid, queue);
const isEqual = orangeCount === rottenCount;
return isEqual ? minutes : -1;
};
const searchGrid = (grid, orangeCount = 0, queue = new Queue([])) => {
const [rows, cols] = [grid.length, grid[0].length];
for (let row = 0; row < rows; row++) {
for (let col = 0; col < cols; col++) {
const isEmpty = grid[row][col] === 0;
if (!isEmpty) orangeCount++;
const isRotten = grid[row][col] === 2;
if (isRotten) queue.enqueue([row, col]);
}
}
return { queue, orangeCount };
};
const bfs = (grid, queue, rottenCount = 0, minutes = 0) => {
while (!queue.isEmpty()) {
rottenCount += queue.size();
for (let i = queue.size() - 1; 0 <= i; i--) {
expireFresh(grid, queue);
}
if (queue.size()) minutes++;
}
return { rottenCount, minutes };
};
var expireFresh = (grid, queue) => {
const [rows, cols] = [grid.length, grid[0].length];
const [row, col] = queue.dequeue();
for (const [_row, _col] of getNeighbors(row, rows, col, cols)) {
const isFresh = grid[_row][_col] === 1;
if (!isFresh) continue;
grid[_row][_col] = 2;
queue.enqueue([_row, _col]);
}
};
var getNeighbors = (row, rows, col, cols) =>
[
[0, 1],
[0, -1],
[1, 0],
[-1, 0],
]
.map(([_row, _col]) => [row + _row, col + _col])
.filter(
([_row, _col]) =>
0 <= _row && _row < rows && 0 <= _col && _col < cols,
);
* https://leetcode.com/problems/rotting-oranges/
* Time O((ROWS * COLS)^2) | Space O(1)
* @param {number[][]} grid
* @return {number}
*/
var orangesRotting = function (grid, minutes = 2) {
while (expireFresh(grid, minutes)) minutes++;
return !hasFresh(grid) ? minutes - 2 : -1;
};
var expireFresh = (grid, minutes, toBeContinued = false) => {
const [rows, cols] = [grid.length, grid[0].length];
for (let row = 0; row < rows; row++) {
for (let col = 0; col < cols; col++) {
const isEqual = grid[row][col] === minutes;
if (!isEqual) continue;
for (const [_row, _col] of getNeighbors(row, rows, col, cols)) {
const isFresh = grid[_row][_col] === 1;
if (!isFresh) continue;
grid[_row][_col] = minutes + 1;
toBeContinued = true;
}
}
}
return toBeContinued;
};
var getNeighbors = (row, rows, col, cols) =>
[
[0, 1],
[0, -1],
[1, 0],
[-1, 0],
]
.map(([_row, _col]) => [row + _row, col + _col])
.filter(
([_row, _col]) =>
0 <= _row && _row < rows && 0 <= _col && _col < cols,
);
const hasFresh = (grid) => {
for (const row of grid) {
for (const cell of row) {
const isFresh = cell === 1;
if (isFresh) return true;
}
}
return false;
};