Reconstruct a 2-Row Binary Matrix

arraygreedymatrix

Given the following details of a matrix with n columns and 2 rows :

The matrix is a binary matrix, which means each element in the matrix can be 0 or 1 .

The sum of elements of the 0-th(upper) row is given as upper .

The sum of elements of the 1-st(lower) row is given as lower .

The sum of elements in the i-th column(0-indexed) is colsum[i] , where colsum is given as an integer array with length n .

Your task is to reconstruct the matrix with upper , lower and colsum .

Return it as a 2-D integer array.

If there are more than one valid solution, any of them will be accepted.

If no valid solution exists, return an empty 2-D array.

Example 1

Input: upper = 2, lower = 1, colsum = [1,1,1]
Output: [[1,1,0],[0,0,1]]
[[1,0,1],[0,1,0]], and [[0,1,1],[1,0,0]] are also correct answers.

Example 2

Input: upper = 2, lower = 3, colsum = [2,2,1,1]
Output: []

Example 3

Input: upper = 5, lower = 5, colsum = [2,1,2,0,1,0,1,2,0,1]
Output: [[1,1,1,0,1,0,0,1,0,0],[1,0,1,0,0,0,1,1,0,1]]

1 <= colsum.length <= 10^5

0 <= upper, lower <= colsum.length

0 <= colsum[i] <= 2

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicGreedy