Merge pull request #355 from z80160280/z80160280-patch-4

Update 0123.买卖股票的最佳时机III.md

problems/0123.买卖股票的最佳时机III.md

@@ -229,6 +229,40 @@ class Solution { // 动态规划
 
 Python：
 
+> 版本一：
+```python
+class Solution:
+    def maxProfit(self, prices: List[int]) -> int:
+        if len(prices) == 0:
+            return 0
+        dp = [[0] * 5 for _ in range(len(prices))]
+        dp[0][1] = -prices[0]
+        dp[0][3] = -prices[0]
+        for i in range(1, len(prices)):
+            dp[i][0] = dp[i-1][0]
+            dp[i][1] = max(dp[i-1][1], dp[i-1][0] - prices[i])
+            dp[i][2] = max(dp[i-1][2], dp[i-1][1] + prices[i])
+            dp[i][3] = max(dp[i-1][3], dp[i-1][2] - prices[i])
+            dp[i][4] = max(dp[i-1][4], dp[i-1][3] + prices[i])
+        return dp[-1][4]
+```
+
+> 版本二：
+```python
+class Solution:
+    def maxProfit(self, prices: List[int]) -> int:
+        if len(prices) == 0:
+            return 0
+        dp = [0] * 5 
+        dp[1] = -prices[0]
+        dp[3] = -prices[0]
+        for i in range(1, len(prices)):
+            dp[1] = max(dp[1], dp[0] - prices[i])
+            dp[2] = max(dp[2], dp[1] + prices[i])
+            dp[3] = max(dp[3], dp[2] - prices[i])
+            dp[4] = max(dp[4], dp[3] + prices[i])
+        return dp[4]
+```
 
 Go：