二刷121

Author: diguage

Diff for: docs/0121-best-time-to-buy-and-sell-stock.adoc

@@ -24,43 +24,37 @@ Output: 0
 Explanation: In this case, no transaction is done, i.e. max profit = 0.
 ----
 
-针对 https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/solution/yi-ge-fang-fa-tuan-mie-6-dao-gu-piao-wen-ti-by-lab/[一个方法团灭 6 道股票问题 - 最佳买卖股票时机含冷冻期 - 力扣（LeetCode）^] 这个解题框架，进行小试牛刀。
+== 思路分析
 
-== 参考资料
-
-. https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/solution/yi-ge-fang-fa-tuan-mie-6-dao-gu-piao-wen-ti-by-lab/[一个方法团灭 6 道股票问题 - 最佳买卖股票时机含冷冻期 - 力扣（LeetCode）^]
-. https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/solution/dong-tai-gui-hua-shen-ru-fen-xi-by-wang-yan-19/[动态规划深入分析 - 最佳买卖股票时机含冷冻期 - 力扣（LeetCode）^]
+一次遍历，在遍历中找最大值减去最小值即可。
 
-Say you have an array for which the _i_^th^ element is the price of a given stock on day _i_.
+image::images/0121-01.gif[{image_attr}]
 
-If you were only permitted to complete at most one transaction (i.e., buy one and sell one share of the stock), design an algorithm to find the maximum profit.
-
-Note that you cannot sell a stock before you buy one.
-
-*Example 1:*
-
-[subs="verbatim,quotes,macros"]
+[[src-0121]]
+[tabs]
+====
+一刷::
++
+--
+[{java_src_attr}]
 ----
-*Input:* [7,1,5,3,6,4]
-*Output:* 5
-*Explanation:* Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
-             Not 7-1 = 6, as selling price needs to be larger than buying price.
+include::{sourcedir}/_0121_BestTimeToBuyAndSellStock.java[tag=answer]
 ----
+--
 
-*Example 2:*
-
-[subs="verbatim,quotes,macros"]
+二刷::
++
+--
+[{java_src_attr}]
 ----
-*Input:* [7,6,4,3,1]
-*Output:* 0
-*Explanation:* In this case, no transaction is done, i.e. max profit = 0.
+include::{sourcedir}/_0121_BestTimeToBuyAndSellStock_2.java[tag=answer]
 ----
+--
+====
 
 
+== 参考资料
 
-[[src-0121]]
-[{java_src_attr}]
-----
-include::{sourcedir}/_0121_BestTimeToBuyAndSellStock.java[tag=answer]
-----
-
+. https://leetcode.cn/problems/best-time-to-buy-and-sell-stock-with-cooldown/solutions/8610/yi-ge-fang-fa-tuan-mie-6-dao-gu-piao-wen-ti-by-lab/[309. 买卖股票的最佳时机含冷冻期 - 一个方法团灭 6 道股票问题^]
+. https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/solution/dong-tai-gui-hua-shen-ru-fen-xi-by-wang-yan-19/[动态规划深入分析 - 最佳买卖股票时机含冷冻期 - 力扣（LeetCode）^]
+. https://leetcode.cn/problems/best-time-to-buy-and-sell-stock/solutions/1692872/by-jyd-cu90/[121. 买卖股票的最佳时机 - 动态规划，清晰图解^]

Diff for: docs/images/0121-01.gif

@@ -570,6 +570,11 @@
 |{doc_base_url}/0236-lowest-common-ancestor-of-a-binary-tree.adoc[题解]
 |想清楚怎么判断是否为公共祖先。
 
+|{counter:codes}
+|{leetcode_base_url}/best-time-to-buy-and-sell-stock/[121. Best Time to Buy and Sell Stock^]
+|{doc_base_url}/0121-best-time-to-buy-and-sell-stock.adoc[题解]
+|
+
 |===
 
 截止目前，本轮练习一共完成 {codes} 道题。

Diff for: logbook/202406.adoc

@@ -40,6 +40,9 @@ public class _0121_BestTimeToBuyAndSellStock {
      * Memory Usage: 42.6 MB, less than 5.31% of Java online submissions for Best Time to Buy and Sell Stock.
      *
      * Copy from: https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-with-cooldown/solution/yi-ge-fang-fa-tuan-mie-6-dao-gu-piao-wen-ti-by-lab/[一个方法团灭 6 道股票问题 - 最佳买卖股票时机含冷冻期 - 力扣（LeetCode）]
+     *
+     * @author D瓜哥 · https://www.diguage.com
+     * @since 2020-01-01 13:01
      */
     public int maxProfitDp(int[] prices) {
         int dp0 = 0;

Diff for: src/main/java/com/diguage/algo/leetcode/_0121_BestTimeToBuyAndSellStock.java

@@ -0,0 +1,19 @@
+package com.diguage.algo.leetcode;
+
+public class _0121_BestTimeToBuyAndSellStock_2 {
+  // tag::answer[]
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2024-09-15 07:44:20
+   */
+  public int maxProfit(int[] prices) {
+    int result = 0;
+    int min = 100000;
+    for (int p : prices) {
+      min = Math.min(min, p);
+      result = Math.max(result, p - min);
+    }
+    return result;
+  }
+  // end::answer[]
+}