- Difficulty: Medium
- Tags: LeetCode, Medium, Array, Dynamic Programming, Matrix, leetcode-3122, O(n * (m + 10)), O(10), DP
Problem
You are given a 2D matrix grid
of size m x n
. In one operation, you can change the value of any cell to any non-negative number. You need to perform some operations such that each cell grid[i][j]
is:
- Equal to the cell below it, i.e.
grid[i][j] == grid[i + 1][j]
(if it exists). - Different from the cell to its right, i.e.
grid[i][j] != grid[i][j + 1]
(if it exists).
Return the minimum number of operations needed.
Example 1:
Input: grid = [[1,0,2],[1,0,2]]
Output: 0
Explanation:
All the cells in the matrix already satisfy the properties.
Example 2:
Input: grid = [[1,1,1],[0,0,0]]
Output: 3
Explanation:
The matrix becomes [[1,0,1],[1,0,1]]
which satisfies the properties, by doing these 3 operations:
- Change
grid[1][0]
to 1. - Change
grid[0][1]
to 0. - Change
grid[1][2]
to 1.
Example 3:
Input: grid = [[1],[2],[3]]
Output: 2
Explanation:
There is a single column. We can change the value to 1 in each cell using 2 operations.
Constraints:
1 <= n, m <= 1000
0 <= grid[i][j] <= 9