add leetcode

AmrikSD · Mar 6, 2024 · 6fd7ca2 · 6fd7ca2
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diff --git a/projects/Leetcode/.gitignore b/projects/Leetcode/.gitignore
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+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+# https://github.com/takari/maven-wrapper#usage-without-binary-jar
+.mvn/wrapper/maven-wrapper.jar
+
+.settings/
+
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+*.code-workspace
+
+# Local History for Visual Studio Code
+.history/
+.project
+.classpath
diff --git a/projects/Leetcode/README.md b/projects/Leetcode/README.md
@@ -0,0 +1,129 @@
+# Need to Revisit
+
+- 1775 - [Equal Sum Arrays With Minimum Number of Operations](https://leetcode.com/problems/equal-sum-arrays-with-minimum-number-of-operations/)
+  Topics: Array, Hash Table, Greedy, Counting
+
+- 337 - [House Robber III](https://leetcode.com/problems/house-robber-iii/)
+  Topics: Binary Tree
+
+- 766 - [Toeplitz Matrix](https://leetcode.com/problems/toeplitz-matrix/)
+  Topics: Array, Matrix
+
+# Done
+
+## Easy
+
+- 1 - [Two Sum](https://leetcode.com/problems/two-sum/)
+- 1189 - [Maximum Number of Balloons](https://leetcode.com/problems/maximum-number-of-balloons/)
+
+## Medium
+
+- 1493 - [Longest Subarray of 1s After Deleting One Element](https://leetcode.com/problems/longest-subarray-of-1s-after-deleting-one-element)
+
+# 'The' 75
+
+## Array
+
+- [x] [Two Sum](https://leetcode.com/problems/two-sum/)
+- [ ] [Best Time to Buy and Sell Stock](https://leetcode.com/problems/best-time-to-buy-and-sell-stock/)
+- [x] [Contains Duplicate](https://leetcode.com/problems/contains-duplicate/)
+- [ ] [Product of Array Except Self](https://leetcode.com/problems/product-of-array-except-self/)
+- [ ] [Maximum Subarray](https://leetcode.com/problems/maximum-subarray/)
+- [ ] [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/)
+- [ ] [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/)
+- [ ] [Search in Rotated Sorted Array](https://leetcode.com/problems/search-in-rotated-sorted-array/)
+- [ ] [3 Sum](https://leetcode.com/problems/3sum/)
+- [ ] [Container With Most Water](https://leetcode.com/problems/container-with-most-water/)
+
+## Binary
+
+- [ ] [Sum of Two Integers](https://leetcode.com/problems/sum-of-two-integers/)
+- [ ] [Number of 1 Bits](https://leetcode.com/problems/number-of-1-bits/)
+- [ ] [Counting Bits](https://leetcode.com/problems/counting-bits/)
+- [ ] [Missing Number](https://leetcode.com/problems/missing-number/)
+- [ ] [Reverse Bits](https://leetcode.com/problems/reverse-bits/)
+
+## Dynamic Programming
+
+- [x] [Climbing Stairs](https://leetcode.com/problems/climbing-stairs/)
+- [ ] [Coin Change](https://leetcode.com/problems/coin-change/)
+- [ ] [Longest Increasing Subsequence](https://leetcode.com/problems/longest-increasing-subsequence/)
+- [ ] [Longest Common Subsequence](https://leetcode.com/problems/longest-common-subsequence/)
+- [ ] [Word Break Problem](https://leetcode.com/problems/word-break/)
+- [ ] [Combination Sum](https://leetcode.com/problems/combination-sum-iv/)
+- [ ] [House Robber](https://leetcode.com/problems/house-robber/)
+- [ ] [House Robber II](https://leetcode.com/problems/house-robber-ii/)
+- [ ] [Decode Ways](https://leetcode.com/problems/decode-ways/)
+- [ ] [Unique Paths](https://leetcode.com/problems/unique-paths/)
+- [ ] [Jump Game](https://leetcode.com/problems/jump-game/)
+
+## Graph
+
+- [ ] [Clone Graph](https://leetcode.com/problems/clone-graph/)
+- [ ] [Course Schedule](https://leetcode.com/problems/course-schedule/)
+- [ ] [Pacific Atlantic Water Flow](https://leetcode.com/problems/pacific-atlantic-water-flow/)
+- [x] [Number of Islands](https://leetcode.com/problems/number-of-islands/)
+- [ ] [Longest Consecutive Sequence](https://leetcode.com/problems/longest-consecutive-sequence/)
+- [ ] [Alien Dictionary](https://leetcode.com/problems/alien-dictionary/)
+- [ ] [Graph Valid Tree](https://leetcode.com/problems/graph-valid-tree/)
+- [ ] [Number of Connected Components in an Undirected Graph](https://leetcode.com/problems/number-of-connected-components-in-an-undirected-graph/)
+
+## Interval
+
+- [ ] [Insert Interval](https://leetcode.com/problems/insert-interval/)
+- [ ] [Merge Intervals](https://leetcode.com/problems/merge-intervals/)
+- [ ] [Non-overlapping Intervals](https://leetcode.com/problems/non-overlapping-intervals/)
+- [ ] [Meeting Rooms](https://leetcode.com/problems/meeting-rooms/)
+- [ ] [Meeting Rooms II](https://leetcode.com/problems/meeting-rooms-ii/)
+
+## Linked List
+
+- [ ] [Reverse a Linked List](https://leetcode.com/problems/reverse-linked-list/)
+- [ ] [Detect Cycle in a Linked List](https://leetcode.com/problems/linked-list-cycle/)
+- [ ] [Merge Two Sorted Lists](https://leetcode.com/problems/merge-two-sorted-lists/)
+- [ ] [Merge K Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/)
+- [ ] [Remove Nth Node From End Of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/)
+- [ ] [Reorder List](https://leetcode.com/problems/reorder-list/)
+
+## Matrix
+
+- [ ] [Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/)
+- [ ] [Spiral Matrix](https://leetcode.com/problems/spiral-matrix/)
+- [ ] [Rotate Image](https://leetcode.com/problems/rotate-image/)
+- [ ] [Word Search](https://leetcode.com/problems/word-search/)
+
+## String
+
+- [ ] [Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/)
+- [ ] [Longest Repeating Character Replacement](https://leetcode.com/problems/longest-repeating-character-replacement/)
+- [ ] [Minimum Window Substring](https://leetcode.com/problems/minimum-window-substring/)
+- [ ] [Valid Anagram](https://leetcode.com/problems/valid-anagram/)
+- [ ] [Group Anagrams](https://leetcode.com/problems/group-anagrams/)
+- [ ] [Valid Parentheses](https://leetcode.com/problems/valid-parentheses/)
+- [ ] [Valid Palindrome](https://leetcode.com/problems/valid-palindrome/)
+- [ ] [Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/)
+- [ ] [Palindromic Substrings](https://leetcode.com/problems/palindromic-substrings/)
+- [ ] [Encode and Decode Strings](https://leetcode.com/problems/encode-and-decode-strings/)
+
+## Tree
+
+- [x] [Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/)
+- [ ] [Same Tree](https://leetcode.com/problems/same-tree/)
+- [ ] [Invert/Flip Binary Tree](https://leetcode.com/problems/invert-binary-tree/)
+- [ ] [Binary Tree Maximum Path Sum](https://leetcode.com/problems/binary-tree-maximum-path-sum/)
+- [ ] [Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/)
+- [ ] [Serialize and Deserialize Binary Tree](https://leetcode.com/problems/serialize-and-deserialize-binary-tree/)
+- [ ] [Subtree of Another Tree](https://leetcode.com/problems/subtree-of-another-tree/)
+- [ ] [Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/)
+- [ ] [Validate Binary Search Tree](https://leetcode.com/problems/validate-binary-search-tree/)
+- [ ] [Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/)
+- [ ] [Lowest Common Ancestor of BST](https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-search-tree/)
+- [ ] [Implement Trie (Prefix Tree)](https://leetcode.com/problems/implement-trie-prefix-tree/)
+- [ ] [Add and Search Word](https://leetcode.com/problems/add-and-search-word-data-structure-design/)
+- [ ] [Word Search II](https://leetcode.com/problems/word-search-ii/)
+
+## Heap
+
+- [ ] [Merge K Sorted Lists](https://leetcode.com/problems/merge-k-sorted-lists/)
+- [ ] [Top K Frequent Elements](https://leetcode.com/problems/top-k-frequent-elements/)
+- [ ] [Find Median from Data Stream](https://leetcode.com/problems/find-median-from-data-stream/)
diff --git a/projects/Leetcode/pom.xml b/projects/Leetcode/pom.xml
@@ -0,0 +1,75 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>de.amrik</groupId>
+  <artifactId>Leetcode</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <name>Leetcode</name>
+  <!-- FIXME change it to the project's website -->
+  <url>https://amrik.de/CV</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <maven.compiler.source>1.7</maven.compiler.source>
+    <maven.compiler.target>1.7</maven.compiler.target>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.11</version>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <pluginManagement>
+      <!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
+      <plugins>
+        <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
+        <plugin>
+          <artifactId>maven-clean-plugin</artifactId>
+          <version>3.1.0</version>
+        </plugin>
+        <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
+        <plugin>
+          <artifactId>maven-resources-plugin</artifactId>
+          <version>3.0.2</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <version>3.8.0</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-surefire-plugin</artifactId>
+          <version>2.22.1</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-jar-plugin</artifactId>
+          <version>3.0.2</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-install-plugin</artifactId>
+          <version>2.5.2</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-deploy-plugin</artifactId>
+          <version>2.8.2</version>
+        </plugin>
+        <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
+        <plugin>
+          <artifactId>maven-site-plugin</artifactId>
+          <version>3.7.1</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-project-info-reports-plugin</artifactId>
+          <version>3.0.0</version>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+  </build>
+</project>
diff --git a/projects/Leetcode/src/main/java/de/amrik/ClimbingStairs.java b/projects/Leetcode/src/main/java/de/amrik/ClimbingStairs.java
@@ -0,0 +1,17 @@
+package de.amrik;
+
+import java.util.HashMap;
+
+public class ClimbingStairs {
+    public static int waysToClimbStairs(int n) {
+        HashMap<Integer, Integer> hm = new HashMap<Integer, Integer>(n);
+        for (int i = 1; i <= 2; i++) {
+            hm.put(i, i);
+        }
+        for (int i = 3; i <= n; i++) {
+            hm.put(i, (hm.get(i - 1) + hm.get(i - 2)));
+        }
+        return hm.get(n);
+
+    }
+}
diff --git a/projects/Leetcode/src/main/java/de/amrik/ContainsDuplicate.java b/projects/Leetcode/src/main/java/de/amrik/ContainsDuplicate.java
@@ -0,0 +1,19 @@
+package de.amrik;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class ContainsDuplicate {
+
+    public static boolean containsDuplicate(int[] arr) {
+        Set<Integer> hs = new HashSet<>(arr.length);
+        for (int i : arr) {
+            if (hs.contains(i)) {
+                return true;
+            }
+            hs.add(i);
+        }
+        return false;
+    }
+
+}
diff --git a/projects/Leetcode/src/main/java/de/amrik/DataStructures/TreeNode.java b/projects/Leetcode/src/main/java/de/amrik/DataStructures/TreeNode.java
@@ -0,0 +1,43 @@
+package de.amrik.DataStructures;
+
+public class TreeNode {
+
+    public int val;
+    public TreeNode left;
+    public TreeNode right;
+
+    TreeNode() {
+    }
+
+    TreeNode(int val) {
+        this.val = val;
+    }
+
+    TreeNode(int val, TreeNode left, TreeNode right) {
+        this.val = val;
+        this.left = left;
+        this.right = right;
+    }
+
+    public static TreeNode fromArray(Integer[] arr) {
+        if (arr.length == 0) {
+            return null;
+        }
+        TreeNode root = new TreeNode(arr[0]);
+        return fromArray(arr, root, 0);
+    }
+
+    static TreeNode fromArray(Integer[] arr, TreeNode root, int depth) {
+        if (depth < arr.length) {
+            if (arr[depth] == null) {
+                return null;
+            }
+            TreeNode temp = new TreeNode(arr[depth]);
+            root = temp;
+            root.left = fromArray(arr, root.left, depth * 2 + 1);
+            root.right = fromArray(arr, root.right, depth * 2 + 2);
+        }
+        return root;
+    }
+
+}
diff --git a/projects/Leetcode/src/main/java/de/amrik/LongestSubarrayOfOnesAfterDeletingOneElement.java b/projects/Leetcode/src/main/java/de/amrik/LongestSubarrayOfOnesAfterDeletingOneElement.java
@@ -0,0 +1,46 @@
+package de.amrik;
+
+import java.util.Arrays;
+
+public class LongestSubarrayOfOnesAfterDeletingOneElement {
+
+    /**
+     * Given a binary array nums, you should delete one element from it.
+     * 
+     * @return the size of the longest non-empty subarray containing only 1's in the
+     *         resulting array. Return 0 if there is no such subarray.
+     */
+    public static int getLengthOfSubarray(int[] nums) {
+
+        // If we have all 0s in the array, return 0.
+        if (Arrays.stream(nums).sum() == 0) {
+            return 0;
+        }
+        if (Arrays.stream(nums).sum() >= nums.length - 1) {
+            return nums.length - 1;
+        }
+        int maxSeen = 0;
+        int left = 0;
+        int right = 0;
+
+        for (int i = 0; i < nums.length; i++) {
+            left += nums[i];
+
+            if (nums[i] == 0) {
+                for (int j = i + 1; j < nums.length; j++) {
+                    right += nums[j];
+                    if (nums[j] == 0 || j == nums.length - 1) {
+                        i = j - 1;
+                        maxSeen = Math.max(maxSeen, left + right);
+                        left = right;
+                        right = 0;
+                        break;
+                    }
+                }
+            }
+
+        }
+
+        return maxSeen;
+    }
+}