[Leetcode] Random flip matrix randomly flipped matrices

You is given the number of rows and number of n_rows columns of n_cols a 2D binary matrix where all values is initially 0. Write a function flip which chooses a 0 value uniformly at random, changes it to 1, and then returns the position [row.id, col.id] of that value. Also, write a function reset which sets all values 0. Try to minimize the number of calls to System ' s math.random () and optimize the time and space complexity.

Note:

1. 1 <= n_rows, n_cols <= 10000
2. 0 <= row.id < n_rowsand0 <= col.id < n_cols
3. flipWon't is called when the matrix have no 0 values left.
4. The total number of calls to and would not flip reset exceed 1000.

Example 1:

["Solution", "Flip", "Flip", "Flip", "Flip")  [null,[0,1],[1,2],[1,0],[1,1]]

Example 2:

["Solution", "Flip", "Flip", "Reset", "Flip")  [null,[0,0],[0,1],null,[0,0]]

Explanation of Input Syntax:

The input is a lists:the subroutines called and their arguments. Solution' s constructor has a arguments, and. and has n_rows n_cols flip reset no arguments. Arguments is always wrapped with a list, even if there aren ' t.

S

[Leetcode] Random flip matrix randomly flipped matrices