From c4a7033e50a8713808654ac4b179ca4883b4998f Mon Sep 17 00:00:00 2001
From: fwqaaq <fwqaaq@gmail.com>
Date: Fri, 30 Jun 2023 13:45:44 +0800
Subject: [PATCH] =?UTF-8?q?Update=200188.=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=BAIV.md?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../0188.买卖股票的最佳时机IV.md     | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/problems/0188.买卖股票的最佳时机IV.md b/problems/0188.买卖股票的最佳时机IV.md
index 8cfb4c1b..fb1a6898 100644
--- a/problems/0188.买卖股票的最佳时机IV.md
+++ b/problems/0188.买卖股票的最佳时机IV.md
@@ -462,6 +462,33 @@ impl Solution {
 }
 ```
 
+空间优化：
+
+```rust
+impl Solution {
+    pub fn max_profit(k: i32, prices: Vec<i32>) -> i32 {
+        let mut dp = vec![0; 2 * k as usize + 1];
+        for v in dp.iter_mut().skip(1).step_by(2) {
+            *v = -prices[0];
+        }
+
+        for p in prices {
+            for i in 1..=2 * k as usize {
+                if i % 2 == 1 {
+                    // 买入
+                    dp[i] = dp[i].max(dp[i - 1] - p);
+                    continue;
+                }
+                // 卖出
+                dp[i] = dp[i].max(dp[i - 1] + p);
+            }
+        }
+
+        dp[2 * k as usize]
+    }
+}
+```
+
 
 <p align="center">
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">