From 44afcb2b898f571be7c6b5ab10b33470612e98e2 Mon Sep 17 00:00:00 2001
From: wzs <1014355013@qq.com>
Date: Wed, 12 May 2021 23:21:50 +0800
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---
 problems/0121.买卖股票的最佳时机.md | 30 +++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/problems/0121.买卖股票的最佳时机.md b/problems/0121.买卖股票的最佳时机.md
index 3d564892..941d4397 100644
--- a/problems/0121.买卖股票的最佳时机.md
+++ b/problems/0121.买卖股票的最佳时机.md
@@ -196,9 +196,37 @@ public:
 
 ## 其他语言版本
 
-
 Java：
 
+``` java
+class Solution { // 动态规划解法
+    public int maxProfit(int[] prices) {
+        // 可交易次数
+        int k = 1;
+        // [天数][交易次数][是否持有股票]
+        int[][][] dp = new int[prices.length][k + 1][2];
+
+        // bad case
+        dp[0][0][0] = 0;
+        dp[0][0][1] = Integer.MIN_VALUE;
+        dp[0][1][0] = Integer.MIN_VALUE;
+        dp[0][1][1] = -prices[0];
+
+        for (int i = 1; i < prices.length; i++) {
+            for (int j = k; j >= 1; j--) {
+                // dp公式
+                dp[i][j][0] = Math.max(dp[i - 1][j][0], dp[i - 1][j][1] + prices[i]);
+                dp[i][j][1] = Math.max(dp[i - 1][j][1], dp[i - 1][j - 1][0] - prices[i]);
+            }
+        }
+
+        return dp[prices.length - 1][k][0] > 0 ? dp[prices.length - 1][k][0] : 0;
+    }
+}
+```
+
+
+
 
 Python：