#1591
Strange Printer II
hard · verified · 60.7% accepted · 691 likes · top 60%
array · graph theory · topological sort · matrix
Description
There is a strange printer with the following two special requirements:
- On each turn, the printer will print a solid rectangular pattern of a single color on the grid. This will cover up the existing colors in the rectangle.
- Once the printer has used a color for the above operation, the same color cannot be used again.
You are given a m x n matrix targetGrid, where targetGrid[row][col] is the color in the position (row, col) of the grid.
Return true if it is possible to print the matrix targetGrid, otherwise, return false.
Example 1:
Input: targetGrid = [[1,1,1,1],[1,2,2,1],[1,2,2,1],[1,1,1,1]]
Output: true
Example 2:
Input: targetGrid = [[1,1,1,1],[1,1,3,3],[1,1,3,4],[5,5,1,4]]
Output: true
Example 3:
Input: targetGrid = [[1,2,1],[2,1,2],[1,2,1]]
Output: false
Explanation: It is impossible to form targetGrid because it is not allowed to print the same color in different turns.
Solution