From 7536f40282677bf2da6b80fe0066e325027b3bb1 Mon Sep 17 00:00:00 2001
From: yennanliu <f339339@gmail.com>
Date: Sat, 11 May 2024 17:08:48 +0800
Subject: [PATCH] update 121 java, progress

---
 data/progress.txt                             |  1 +
 data/to_review.txt                            | 11 +++++-
 .../Array/BestTimeToBuyAndSellStock.java      | 38 ++++++++++++++++++
 .../src/main/java/dev/workspace3.java         | 39 +++++++++++++++++++
 4 files changed, 87 insertions(+), 2 deletions(-)

diff --git a/data/progress.txt b/data/progress.txt
index bd237989..d74b004d 100644
--- a/data/progress.txt
+++ b/data/progress.txt
@@ -1,3 +1,4 @@
+20240511: 121,252
 20240510: 125
 20240314: 647
 20240313: 338,347,371,417(again),424(again),435,572(again)
diff --git a/data/to_review.txt b/data/to_review.txt
index f9b82e78..b51942da 100644
--- a/data/to_review.txt
+++ b/data/to_review.txt
@@ -1,11 +1,18 @@
+2024-07-05 -> ['121,252']
 2024-07-04 -> ['125']
+2024-06-14 -> ['121,252']
 2024-06-13 -> ['125']
+2024-06-01 -> ['121,252']
 2024-05-31 -> ['125']
+2024-05-24 -> ['121,252']
 2024-05-23 -> ['125']
+2024-05-19 -> ['121,252']
 2024-05-18 -> ['125']
+2024-05-16 -> ['121,252']
 2024-05-15 -> ['125']
-2024-05-13 -> ['125']
-2024-05-12 -> ['125']
+2024-05-14 -> ['121,252']
+2024-05-13 -> ['121,252', '125']
+2024-05-12 -> ['121,252', '125']
 2024-05-11 -> ['125']
 2024-05-07 -> ['338,347,371,417(again),424(again),435,572(again)']
 2024-05-06 -> ['297(again),300,322(again),323']
diff --git a/leetcode_java/src/main/java/LeetCodeJava/Array/BestTimeToBuyAndSellStock.java b/leetcode_java/src/main/java/LeetCodeJava/Array/BestTimeToBuyAndSellStock.java
index 2fde3d4a..136bc0d7 100644
--- a/leetcode_java/src/main/java/LeetCodeJava/Array/BestTimeToBuyAndSellStock.java
+++ b/leetcode_java/src/main/java/LeetCodeJava/Array/BestTimeToBuyAndSellStock.java
@@ -7,6 +7,44 @@ public class BestTimeToBuyAndSellStock {
     // V0
     public int maxProfit(int[] prices) {
 
+        if (prices.length == 0){
+            return 0;
+        }
+
+        int res = 0;
+        int min = -1;
+        int max = -1;
+
+        for (int i : prices){
+            int cur = i;
+            //System.out.println("cur = " + cur);
+            if (min == -1){
+                min = cur;
+                continue;
+            }
+            if (min > cur){
+                min = cur;
+                continue;
+            }
+            if (max == -1){
+                max = cur;
+            }
+            if (cur > max){
+                max = cur;
+            }
+            int tmp = max - min;
+            //System.out.println("max = " + max + " min = " + min + " tmp = " + tmp);
+            /** NOTE : need to reset max val after get "revenue", so we don't reuse previous max val */
+            max = -1;
+            res = Math.max(tmp, res);
+        }
+
+        return res;
+    }
+
+    // V0'
+    public int maxProfit_0(int[] prices) {
+
         int minVal = (int) Math.pow(10, 4);
         int maxVal = 0;
         int maxProfit = 0;
diff --git a/leetcode_java/src/main/java/dev/workspace3.java b/leetcode_java/src/main/java/dev/workspace3.java
index 15f17cff..b432cb81 100644
--- a/leetcode_java/src/main/java/dev/workspace3.java
+++ b/leetcode_java/src/main/java/dev/workspace3.java
@@ -42,4 +42,43 @@ public boolean isPalindrome(String s) {
         return sb.toString() == sb.reverse().toString();
     }
 
+    // LC 121
+    public int maxProfit(int[] prices) {
+
+        if (prices.length == 0){
+            return 0;
+        }
+
+        int res = 0;
+        int min = -1;
+        int max = -1;
+
+        for (int i : prices){
+            int cur = i; //prices[i];
+            System.out.println("cur = " + cur);
+            if (min == -1){
+                min = cur;
+                continue;
+            }
+            if (min > cur){
+                min = cur;
+                continue;
+            }
+            if (max == -1){
+                max = cur;
+                max = cur;
+            }
+            if (cur > max){
+                max = cur;
+            }
+            int tmp = max - min;
+            System.out.println("max = " + max + " min = " + min + " tmp = " + tmp);
+            max = -1;
+            res = Math.max(tmp, res);
+        }
+
+        return res;
+    }
+
+
 }