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 be8630f5..9c8a4390 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
@@ -527,6 +527,21 @@ impl Solution {
 }
 ```
 
+> 动态规划
+
+```rust
+impl Solution {
+    pub fn max_profit(prices: Vec<i32>) -> i32 {
+        let mut dp = vec![-prices[0], 0];
+        for p in prices {
+            dp[0] = dp[0].max(-p);
+            dp[1] = dp[1].max(dp[0] + p);
+        }
+        dp[1]
+    }
+}
+```
+
 
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