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]] Explanation: [[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]] Constraints: 1 <= colsum.length <= 10^5 0 <= upper, lower <= colsum.length 0 <= colsum[i] <= 2