A solution for problem walls and gates on leetcode in Solang

leetcode_wallsAndGates.go

// A solution for walls and gates problem on leetcode in golang
package main

import (
	"fmt"
	"math"
)

const EMPTY int = math.MaxInt32
const GATE int = 0
const WALL int = -1

var DIRECTIONS = [4][2]int{{1, 0}, {-1, 0}, {0, 1}, {0, -1}}

type queue struct {
	data [][]int
	head int
}

func (q *queue) enqueue(node []int) {
	q.data = append(q.data, node)
}

func (q *queue) dequeue() []int {
	val := q.data[q.head]
	q.head++
	return val
}

func (q *queue) isEmpty() bool {
	if q.head == len(q.data) {
		return true
	}
	return false
}

func wallsAndGates(rooms [][]int) {
	if len(rooms) == 0 {
		return
	}
	for row := 0; row < len(rooms); row++ {
		for col := 0; col < len(rooms[0]); col++ {
			if rooms[row][col] == EMPTY {
				rooms[row][col] = distanceToNearestGate(rooms, row, col)
			}
		}
	}
}

func distanceToNearestGate(rooms [][]int, startRow int, startCol int) int {
	m := len(rooms)
	n := len(rooms[0])

	var distance [][]int
	distance = make([][]int, m)
	for i := 0; i < m; i++ {
		distance[i] = make([]int, n)
	}

	var q queue

	var node = []int{startRow, startCol}
	q.enqueue(node)
	for !q.isEmpty() {
		point := q.dequeue()
		row := point[0]
		col := point[1]
		for _, direction := range DIRECTIONS {
			r := row + direction[0]
			c := col + direction[1]
			if r < 0 || c < 0 || r >= m || c >= n || rooms[r][c] == WALL || distance[r][c] != 0 {
				continue
			}
			distance[r][c] = distance[row][col] + 1
			if rooms[r][c] == GATE {
				return distance[r][c]
			}
			var newNode = []int{r, c}
			q.enqueue(newNode)
		}
	}
	return math.MaxInt32
}

func main() {
	var rooms = [][]int{{2147483647, -1, 0, 2147483647}, {2147483647, 2147483647, 2147483647, -1}, {2147483647, -1, 2147483647, -1}, {0, -1, 2147483647, 2147483647}}
	wallsAndGates(rooms)
	fmt.Println(rooms)
}

Try this on https://go.dev/play/p/k17qkxo6YVH