fix DataStructure/ListNode.java, relative code, add 369 java

data/progress.md

@@ -1,5 +1,8 @@
 # Progress
 
+# 2024-12-22
+- https://github.com/yennanliu/CS_basics/blob/master/doc/Leetcode_company_frequency-master/Google%206months-%20LeetCode.pdf
+
 # 2024-12-21
 - https://github.com/yennanliu/CS_basics/blob/master/doc/Leetcode_company_frequency-master/Google%206months-%20LeetCode.pdf
 

data/progress.txt

@@ -1,3 +1,4 @@
+20241222: 369
 20241221: 370
 20241220: 815,871,593,1109
 20241214: 560,523

leetcode_java/src/main/java/LeetCodeJava/DataStructure/ListNode.java

@@ -2,24 +2,34 @@
 
 // https://leetcode.com/problems/merge-two-sorted-lists/
 
-public class ListNode{
-
-    // attr
+// V1
+//public class ListNode{
+//
+//    // attr
+//    public int val;
+//    public ListNode next;
+//
+//    // constructor
+//    public ListNode(){
+//
+//    }
+//
+//    public ListNode(int val){
+//        this.val = val;
+//    }
+//
+//    ListNode(int val, ListNode next){
+//        this.val = val;
+//        this.next = next;
+//    }
+//
+//}
+
+// V2
+public class ListNode {
     public int val;
     public ListNode next;
-
-    // constructor
-    public ListNode(){
-
-    }
-
-    public ListNode(int val){
-        this.val = val;
-    }
-
-    ListNode(int val, ListNode next){
-        this.val = val;
-        this.next = next;
-    }
-
+    public ListNode() {}
+    public ListNode(int val) { this.val = val; }
+    public ListNode(int val, ListNode next) { this.val = val; this.next = next; }
 }

leetcode_java/src/main/java/LeetCodeJava/LinkedList/MergeKSortedLists.java

@@ -2,18 +2,20 @@
 
 // https://leetcode.com/problems/merge-k-sorted-lists/
 
+import LeetCodeJava.DataStructure.ListNode;
+
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
 
 
-class ListNode {
-      int val;
-      ListNode next;
-      ListNode() {}
-      ListNode(int val) { this.val = val; }
-      ListNode(int val, ListNode next) { this.val = val; this.next = next; }
-  }
+//public class ListNode {
+//      int val;
+//      ListNode next;
+//      ListNode() {}
+//      ListNode(int val) { this.val = val; }
+//      ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+//  }
 
 public class MergeKSortedLists {
 

leetcode_java/src/main/java/LeetCodeJava/LinkedList/PlusOneLinkedList.java

@@ -0,0 +1,58 @@
+package LeetCodeJava.LinkedList;
+
+// https://leetcode.com/problems/plus-one-linked-list/description/
+// https://leetcode.ca/all/369.html
+
+import LeetCodeJava.DataStructure.ListNode;
+
+/**
+ * 369. Plus One Linked List Given a non-negative integer represented as non-empty a singly linked
+ * list of digits, plus one to the integer.
+ *
+ * <p>You may assume the integer do not contain any leading zero, except the number 0 itself.
+ *
+ * <p>The digits are stored such that the most significant digit is at the head of the list.
+ *
+ * <p>Example :
+ *
+ * <p>Input: [1,2,3] Output: [1,2,4] Difficulty: Medium Lock: Prime Company: Amazon Apple Google
+ */
+public class PlusOneLinkedList {
+
+  /**
+   * Definition for singly-linked list.
+   * public class ListNode {
+   *     int val;
+   *     ListNode next;
+   *     ListNode() {}
+   *     ListNode(int val) { this.val = val; }
+   *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+   * }
+   */
+
+  // V0
+//  public ListNode plusOne(ListNode head) {
+//  }
+
+  // V1
+  // https://leetcode.ca/2016-12-03-369-Plus-One-Linked-List/
+  public ListNode plusOne_1(ListNode head) {
+    ListNode dummy = new ListNode(0, head);
+    ListNode target = dummy;
+    while (head != null) {
+      if (head.val != 9) {
+        target = head;
+      }
+      head = head.next;
+    }
+    ++target.val;
+    target = target.next;
+    while (target != null) {
+      target.val = 0;
+      target = target.next;
+    }
+    return dummy.val == 1 ? dummy : dummy.next;
+  }
+
+  // V2
+}

leetcode_java/src/main/java/LeetCodeJava/LinkedList/ReverseNodesInKGroup.java

@@ -3,6 +3,8 @@
 // https://leetcode.com/problems/reverse-nodes-in-k-group/description/
 // https://neetcode.io/problems/reverse-nodes-in-k-group
 
+import LeetCodeJava.DataStructure.ListNode;
+
 public class ReverseNodesInKGroup {
 
     // V0

leetcode_java/src/main/java/dev/workspace6.java

@@ -1,5 +1,8 @@
 package dev;
 
+
+import LeetCodeJava.DataStructure.ListNode;
+
 import javax.print.DocFlavor;
 import java.util.*;
 
@@ -481,4 +484,63 @@ public int[] getModifiedArray(int length, int[][] updates) {
       return Arrays.copyOfRange(tmp, 0, length); // ????
     }
 
+    // LC 369
+    // https://leetcode.ca/all/369.html
+    // 3.42 PM - 4.00 pm
+    /**
+     *  IDEA 1 : linked list -> int, +1, transform back to linked list
+     *
+     *  Idea 2: do in linked list directly
+     *       -> reverse
+     *       -> add 1, if > 9, move to next digit
+     *       -> reverse again
+     *
+     */
+    // v2
+    public ListNode plusOne(ListNode head) {
+        if (head == null){
+            return new ListNode(1); // ??
+        }
+        ListNode tmp = new ListNode();
+//        // reverse
+//        while(head != null){
+//            ListNode _next = head.next;
+//            ListNode _prev = tmp; // ??
+//            head.next = _prev;
+//            head = _next;
+//        }
+//        tmp.val += 1;  // ??
+
+
+        return null;
+    }
+
+    // v1
+//    public ListNode plusOne_1(ListNode head) {
+//      if (head == null){
+//          return new ListNode(1); // ??
+//      }
+//      List<Integer> list = new ArrayList<>();
+//      while(head != null){
+//          list.add(head.val);
+//          head = head.next;
+//      }
+//      // ???
+//      int cur = 0;
+//      for (int j = list.size(); j >= 0; j--){
+//          cur += (10 ^ j) * list.get(j);
+//      }
+//      cur += 1;
+//      ListNode res = new ListNode();
+//      String string = String.valueOf(cur);
+//      for (String x : string.split("")){
+//          ListNode tmp = new ListNode();
+//          tmp.val = Integer.parseInt(x);
+//          res.next = tmp;
+//          res = res.next;
+//      }
+//
+//      return res;
+//    }
+
 }