Leetcode 1876 Solution

This article provides solution to leetcode question 1876 (map-of-highest-peak)

https://leetcode.com/problems/map-of-highest-peak

Solution

class Solution:
    def highestPeak(self, isWater: List[List[int]]) -> List[List[int]]:
        m = len(isWater)
        n = len(isWater[0])
        heights = [[-1 for _ in range(n)] for _ in range(m)]

        q = collections.deque()
        curr_height = 0

        # Find out all zeros.
        water_pos = []
        for i in range(m):
            for j in range(n):
                if not isWater[i][j]:
                    continue

                heights[i][j] = curr_height
                q.append((i, j))

        while q:
            curr_height += 1

            s = len(q)

            for _ in range(s):
                i, j = q.popleft()

                if i > 0 and heights[i - 1][j] == -1:
                    heights[i - 1][j] = curr_height
                    q.append((i - 1, j))

                if i < m - 1 and heights[i + 1][j] == -1:
                    heights[i + 1][j] = curr_height
                    q.append((i + 1, j))

                if j > 0 and heights[i][j - 1] == -1:
                    heights[i][j - 1] = curr_height
                    q.append((i, j - 1))

                if j < n - 1 and heights[i][j + 1] == -1:
                    heights[i][j + 1] = curr_height
                    q.append((i, j + 1))

        return heights