Update 0474.一和零.md

添加 python3 注释

problems/0474.一和零.md

@@ -190,33 +190,21 @@ class Solution {
 ```
 
 Python：
-
 ```python3
 class Solution:
-    def countBinary(self, s: str) -> (int, int):
-        zeros, ones = 0, 0
-        for c in s:
-            if c == '0':
-                zeros += 1
-            else:
-                ones += 1
-        return zeros, ones
-
     def findMaxForm(self, strs: List[str], m: int, n: int) -> int:
-        dp = [[0]*(n + 1) for _ in range(m + 1)]	# 默认初始化0
+        dp = [[0] * (n + 1) for _ in range(m + 1)]	# 默认初始化0
         # 遍历物品
-        for i in range(len(strs)): 
-            # num_zeros = strs[i].count('0')
-            # num_ones = strs[i].count('1')
-            num_zeros, num_ones = self.countBinary(strs[i])
+        for str in strs:
+            ones = str.count('1')
+            zeros = str.count('0')
             # 遍历背包容量且从后向前遍历！
-            for j in range(m, num_zeros - 1, -1):
-                for i in range(n, num_ones - 1, -1):
-                    dp[j][i] = max(dp[j - num_zeros][i - num_ones] + 1, dp[j][i])
+            for i in range(m, zeros - 1, -1):
+                for j in range(n, ones - 1, -1):
+                    dp[i][j] = max(dp[i][j], dp[i - zeros][j - ones] + 1)
         return dp[m][n]
 ```
 
-
 Go：