Create 1.7 将矩阵中0元素所在行、列清零.md

Author: panxl6

8.1 数组和字符串/1.7 将矩阵中0元素所在行、列清零.md

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+
+## 题目
+编写一个算法，若M x N矩阵中某个元素为0，则将其所在的行与列清零。
+
+## 注解
+首先暴力解，遍历一次矩阵，把0的坐标记忆下来。然后将0所在的行列清零。
+用一个M x N的矩阵记忆有些浪费空间了。对我们而言，有用的只是（x，y）坐标键值对。可以使用一个二维数组(或者字典、元祖)。
+
+这道题还有Follow up
+
+*这道题在LeetCode上有。[https://leetcode.com/problems/set-matrix-zeroes/description/](https://leetcode.com/problems/set-matrix-zeroes/description/)*
+
+
+```python
+class Solution(object):
+    def setZeroes(self, matrix):
+        """
+        :type matrix: List[List[int]]
+        :rtype: void Do not return anything, modify matrix in-place instead.
+        """
+        
+        row_len = len(matrix)
+        if row_len == 0:
+            return
+        
+        col_len = len(matrix[0])
+        if col_len == 0:
+            return
+        
+        row = [0 for i in range(0, col_len)]
+        col = [0 for i in range(0, row_len)]
+        
+        for i in range(0, row_len):
+            for j in range(0, col_len):
+                if matrix[i][j] == 0:
+                    col[i] = row[j] = 1
+                    
+        for i in range(0, row_len):
+            for j in range(0, col_len):
+                if col[i] or row[j]:
+                    matrix[i][j] = 0
+                       
+        
+```