Skip to main content

May-11 2020 Challenge


 11.FloodFill  leetcode premium leetcode premium for free leetcode problems leetcode 200

An image is represented by a 2-D array of integers, each integer representing the pixel value of the image (from 0 to 65535).

Given a coordinate (sr, sc) representing the starting pixel (row and column) of the flood fill, and a pixel value newColor, "flood fill" the image.

To perform a "flood fill", consider the starting pixel, plus any pixels connected 4-directionally to the starting pixel of the same color as the starting pixel, plus any pixels connected 4-directionally to those pixels (also with the same color as the starting pixel), and so on. Replace the color of all of the aforementioned pixels with the newColor.

At the end, return the modified image.

Example 1:

Input: 
image = [[1,1,1],[1,1,0],[1,0,1]]
sr = 1, sc = 1, newColor = 2

Output: [[2,2,2],[2,2,0],[2,0,1]]

Explanation: 
From the center of the image (with position (sr, sc) = (1, 1)), all pixels connected 
by a path of the same color as the starting pixel are colored with the new color.
Note the bottom corner is not colored 2, because it is not 4-directionally connected
to the starting pixel.

Note:

The length of image and image[0] will be in the range [1, 50].
The given starting pixel will satisfy 0 <= sr < image.length and 0 <= sc < image[0].length.
The value of each color in image[i][j] and newColor will be an integer in [0, 65535].

Solution in Java:


class Solution{

public int[][] floodFill(int[][] image, int sr, int sc, int newColor) {
        if (image[sr][sc] != newColor)
            dfs(image, sr, sc, image[sr][sc], newColor);
        return image;
    }

    private void dfs(int[][] image, int i, int j, int c0, int c1) {
        if (i < 0 || j < 0 || i >= image.length || j >= image[0].length || image[i][j] != c0) return;
        image[i][j] = c1;
        dfs(image, i, j - 1, c0, c1);
        dfs(image, i, j + 1, c0, c1);
        dfs(image, i - 1, j, c0, c1);
        dfs(image, i + 1, j, c0, c1);

    }

}
Leetcode day 11



leetcode funding leetcode free premium leetcode friend circle leetcode graph leetcode google leetcode group anagrams leetcode github leetcode google interview questions lis 
leetcode google interview leetcode greedy leetcode gas station leetcode house robber leetcode happy number leetcode hashmap leetcode help center leetcode heap leetcode hard problems leetcode history


Labels:

Comments

Post a Comment

Popular posts from this blog

May-6 2020 Challenge

  6.   Majority Element Given an array of size  n , find the majority element. The majority element is the element that appears  more than   ⌊ n/2 ⌋  times. You may assume that the array is non-empty and the majority element always exist in the array. Example 1: Input: [3,2,3] Output: 3 Example 2: Input: [2,2,1,1,1,2,2] Output: 2 Solution in Java  class Solution {     public int majorityElement(int[] num) {         int m = num[0], cnt= 1;     for (int i = 1; i < num.length; i++) {         if (cnt == 0) {             m= num[i];             cnt = 1;         } else if (num[i] == m) {             cnt++;         } else              cnt--;    }      return m;...
Post a Comment
Read more

Leetcode 424. Longest Repeating Character Replacement. Python (Sliding Window)

  424 .  Longest Repeating Character Replacement You are given a string  s  and an integer  k . You can choose any character of the string and change it to any other uppercase English character. You can perform this operation at most  k  times. Return  the length of the longest substring containing the same letter you can get after performing the above operations .   Example 1: Input: s = "ABAB", k = 2 Output: 4 Explanation: Replace the two 'A's with two 'B's or vice versa. Example 2: Input: s = "AABABBA", k = 1 Output: 4 Explanation: Replace the one 'A' in the middle with 'B' and form "AABBBBA". The substring "BBBB" has the longest repeating letters, which is 4.   Constraints: 1 <= s.length <= 10 5 s  consists of only uppercase English letters. 0 <= k <= s.length Solution :  class Solution: def characterReplacement(self, s: str, k: int) -> int: hm = {} ans = 0 ...
Post a Comment
Read more

Leetcode 190. Reverse Bits. Python. Bit Manipulation

  190 .  Reverse Bits Reverse bits of a given 32 bits unsigned integer. Note: Note that in some languages, such as Java, there is no unsigned integer type. In this case, both input and output will be given as a signed integer type. They should not affect your implementation, as the integer's internal binary representation is the same, whether it is signed or unsigned. In Java, the compiler represents the signed integers using  2's complement notation . Therefore, in  Example 2  above, the input represents the signed integer  -3  and the output represents the signed integer  -1073741825 .   Example 1: Input: n = 00000010100101000001111010011100 Output: 964176192 (00111001011110000010100101000000) Explanation: The input binary string 00000010100101000001111010011100 represents the unsigned integer 43261596, so return 964176192 which its binary representation is 00111001011110000010100101000000 . Example 2: Input: n = 11111111111111111111...
Post a Comment
Read more