LeetCode 1605. Find Valid Matrix Given Row and Column Sums
You are given two arrays rowSum and colSum of non-negative integers
where rowSum[i] is the sum of the elements in the ith row and
colSum[j] is the sum of the elements of the jth column of a 2D matrix.
In other words, you do not know the elements of the matrix, but you do know the sums of each row and column.
Find any matrix of non-negative integers of size rowSum.length x colSum.length that satisfies the rowSum and colSum requirements.
Return a 2D array representing any matrix that fulfills the requirements.
It's guaranteed that at least one matrix that fulfills the requirements exists.
Example 1:
Input: rowSum = [3,8], colSum = [4,7]
Output: [[3,0], [1,7]]
Explanation:
0th row: 3 + 0 = 3 == rowSum[0]
1st row: 1 + 7 = 8 == rowSum[1]
0th column: 3 + 1 = 4 == colSum[0]
1st column: 0 + 7 = 7 == colSum[1]
The row and column sums match, and all matrix elements are non-negative. Another possible matrix is: [[1,2], [3,5]]
Example 2:
Input: rowSum = [5,7,10], colSum = [8,6,8]
Output: [[0,5,0], [6,1,0], [2,0,8]]
Constraints:
1 <= rowSum.length, colSum.length <= 5000 <= rowSum[i], colSum[i] <= 108sum(rowSum) == sum(colSum)
有点像中学的几元一次方程组了，就是但是求解的方式不太一样，就是每次先找到这个行列和的最小值，让这个元素等于这个值，然后行之和减去这个值，列之和减去这个值，一旦行之和或者列之和为0了，就i++ 或者j++;
即可。
Runtime: 1 ms, faster than 100.00% of Java online submissions for Find Valid Matrix Given Row and Column Sums.
Memory Usage: 50.8 MB, less than 27.05% of Java online submissions for Find Valid Matrix Given Row and Column Sums.
