From 4973e988d719a67020cd38de5d6d5e23e1d336d5 Mon Sep 17 00:00:00 2001
From: Baturu <45113401+z80160280@users.noreply.github.com>
Date: Mon, 7 Jun 2021 21:41:42 -0700
Subject: [PATCH] =?UTF-8?q?Update=200122.=E4=B9=B0=E5=8D=96=E8=82=A1?=
 =?UTF-8?q?=E7=A5=A8=E7=9A=84=E6=9C=80=E4=BD=B3=E6=97=B6=E6=9C=BAII?=
 =?UTF-8?q?=EF=BC=88=E5=8A=A8=E6=80=81=E8=A7=84=E5=88=92=EF=BC=89.md?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 ...�票的最佳时机II（动态规划）.md | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/problems/0122.买卖股票的最佳时机II（动态规划）.md b/problems/0122.买卖股票的最佳时机II（动态规划）.md
index ba277fdc..1215025e 100644
--- a/problems/0122.买卖股票的最佳时机II（动态规划）.md
+++ b/problems/0122.买卖股票的最佳时机II（动态规划）.md
@@ -171,6 +171,33 @@ class Solution
 
 Python：
 
+> 版本一：
+```python
+class Solution:
+    def maxProfit(self, prices: List[int]) -> int:
+        length = len(prices)
+        dp = [[0] * 2 for _ in range(length)]
+        dp[0][0] = -prices[0]
+        dp[0][1] = 0
+        for i in range(1, length):
+            dp[i][0] = max(dp[i-1][0], dp[i-1][1] - prices[i]) #注意这里是和121. 买卖股票的最佳时机唯一不同的地方
+            dp[i][1] = max(dp[i-1][1], dp[i-1][0] + prices[i])
+        return dp[-1][1]
+```
+
+> 版本二：
+```python
+class Solution:
+    def maxProfit(self, prices: List[int]) -> int:
+        length = len(prices)
+        dp = [[0] * 2 for _ in range(2)] #注意这里只开辟了一个2 * 2大小的二维数组
+        dp[0][0] = -prices[0]
+        dp[0][1] = 0
+        for i in range(1, length):
+            dp[i % 2][0] = max(dp[(i-1) % 2][0], dp[(i-1) % 2][1] - prices[i])
+            dp[i % 2][1] = max(dp[(i-1) % 2][1], dp[(i-1) % 2][0] + prices[i])
+        return dp[(length-1) % 2][1]
+```
 
 Go：