翻译：更新矩阵。跟经过画盖零线后的矩阵进一步交换增加零元素在未被直线覆盖过的元素中找出最小元素将打√行的各元素减去这个最小元素同时将打√列的各元素加上这个最小元素。

Update the matrix. Further increase the number of zero elements by exchanging the matrix after drawing a zero line, and find the smallest element among the elements that have not been covered by the line. Subtract this minimum element from all elements in the marked rows and add it to all elements in the marked columns.