Package g0801_0900.s0835_image_overlap

Class Solution

java.lang.Object
g0801_0900.s0835_image_overlap.Solution
public class Solution extends java.lang.Object
835 - Image Overlap.

Medium

You are given two images, img1 and img2, represented as binary, square matrices of size n x n. A binary matrix has only 0s and 1s as values.

We translate one image however we choose by sliding all the 1 bits left, right, up, and/or down any number of units. We then place it on top of the other image. We can then calculate the overlap by counting the number of positions that have a 1 in both images.

Note also that a translation does not include any kind of rotation. Any 1 bits that are translated outside of the matrix borders are erased.

Return the largest possible overlap.

Example 1:

Input: img1 = [[1,1,0],[0,1,0],[0,1,0]], img2 = [[0,0,0],[0,1,1],[0,0,1]]

Output: 3

Explanation: We translate img1 to right by 1 unit and down by 1 unit. The number of positions that have a 1 in both images is 3 (shown in red).

Example 2:

Input: img1 = [[1]], img2 = [[1]]

Output: 1

Example 3:

Input: img1 = [[0]], img2 = [[0]]

Output: 0

Constraints:

  • n == img1.length == img1[i].length
  • n == img2.length == img2[i].length
  • 1 <= n <= 30
  • img1[i][j] is either 0 or 1.
  • img2[i][j] is either 0 or 1.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    largestOverlap(int[][] img1, int[][] img2)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • largestOverlap

      public int largestOverlap(int[][] img1, int[][] img2)