feat: azl397985856#73 Add python solution (azl397985856#269)

* Add python solution

Add python solution

* Update 73.set-matrix-zeroes.md

Co-authored-by: lucifer <azl397985856@gmail.com>

Author: jojoxiaojing

problems/73.set-matrix-zeroes.md

@@ -179,6 +179,48 @@ var setZeroes = function(matrix) {
 };
 ```
 Python3 Code:
+
+直接修改第一行和第一列为0的解法：
+```python
+class Solution:
+    def setZeroes(self, matrix: List[List[int]]) -> None:
+        """
+        Do not return anything, modify matrix in-place instead.
+        """
+        def setRowZeros(matrix: List[List[int]], i:int) -> None:
+            C = len(matrix[0])
+            matrix[i] = [0] * C
+        
+        def setColZeros(matrix: List[List[int]], j:int) -> None:
+            R = len(matrix)
+            for i in range(R):
+                matrix[i][j] = 0
+            
+        isCol = False
+        R = len(matrix)
+        C = len(matrix[0])
+        
+        for i in range(R):
+            if matrix[i][0] == 0:
+                isCol = True
+            for j in range(1, C):
+                if matrix[i][j] == 0:
+                    matrix[i][0] = 0
+                    matrix[0][j] = 0
+        for j in range(1, C):
+            if matrix[0][j] == 0:
+                setColZeros(matrix, j)
+                
+        for i in range(R):
+            if matrix[i][0] == 0:
+                setRowZeros(matrix, i)
+        
+        if isCol:
+            setColZeros(matrix, 0)
+
+```
+
+另一种方法是用一个特殊符合标记需要改变的结果，只要这个特殊标记不在我们的题目数据范围（0和1）即可，这里用None。
 ```python
 class Solution:
     def setZeroes(self, matrix: List[List[int]]) -> None: