Examples with ListNode com.pkumar7.datastructures.ListNode used on opensource projects

Example 6 with ListNode

use of com.pkumar7.datastructures.ListNode in project Data-Structures-Algorithms by pankajgangwar.

the class MayW2 method main.

// TODO: 5/15/2020
/* https://leetcode.com/problems/minimum-cost-for-tickets/ */
/* https://leetcode.com/problems/all-oone-data-structure/ */
/* https://leetcode.com/problems/couples-holding-hands/ */
/* https://leetcode.com/problems/increasing-subsequences/ */
/* https://leetcode.com/problems/partition-array-into-three-parts-with-equal-sum/ */
/* https://leetcode.com/problems/minimum-distance-to-type-a-word-using-two-fingers/*/
/* DP on trees */
/* 
       https://leetcode.com/problems/sum-of-distances-in-tree/ 
       https://leetcode.com/problems/minimum-cost-tree-from-leaf-values/
       https://leetcode.com/problems/unique-binary-search-trees-ii/
    */
public static void main(String[] args) {
    MayW2 w2 = new MayW2();
    // w2.leastBricks(new ArrayList<>());
    ListNode head = new ListNode(3);
    head.next = new ListNode(1);
    head.next.next = new ListNode(4);
    head.next.next.next = new ListNode(2);
    // w2.sortList(head);
    List<String> list1 = Arrays.asList("John", "johnsmith@mail.com", "john00@mail.com");
    List<String> list2 = Arrays.asList("John", "johnnybravo@mail.com");
    List<String> list3 = Arrays.asList("John", "johnsmith@mail.com", "john_newyork@mail.com");
    List<String> list4 = Arrays.asList("Mary", "mary@mail.com");
    List<List<String>> accounts = new ArrayList<>();
    accounts.add(list1);
    accounts.add(list2);
    accounts.add(list3);
    accounts.add(list4);
    w2.accountsMerge(accounts);
}

Example 7 with ListNode

use of com.pkumar7.datastructures.ListNode in project Data-Structures-Algorithms by pankajgangwar.

the class JulyW1 method sortedListToBST.

/* LC : 109. Convert Sorted List to Binary Search Tree
    *  https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/
    * https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/
    *  Time : O(nlogn)
    */
public TreeNode sortedListToBST(ListNode head) {
    if (head == null)
        return null;
    if (head.next == null)
        return new TreeNode(head.val);
    ListNode mid = null;
    ListNode fast = head, slow = head;
    ListNode left = head, right = head;
    ListNode prevToMid = head;
    while (fast != null && fast.next != null) {
        fast = fast.next.next;
        prevToMid = slow;
        slow = slow.next;
    }
    mid = slow;
    if (mid != head) {
        prevToMid.next = null;
    } else {
        left = null;
    }
    right = mid.next;
    TreeNode root = new TreeNode(mid.val);
    root.left = sortedListToBST(left);
    root.right = sortedListToBST(right);
    return root;
}

Example 8 with ListNode

use of com.pkumar7.datastructures.ListNode in project Data-Structures-Algorithms by pankajgangwar.

the class JulyW3 method partition.

/* 
    86. Partition List
    https://leetcode.com/problems/partition-list/ */
public ListNode partition(ListNode head, int x) {
    ListNode smallHead = new ListNode(0);
    ListNode biggerHead = new ListNode(0);
    ListNode smaller = smallHead;
    ListNode bigger = biggerHead;
    while (head != null) {
        if (head.val < x) {
            smaller.next = head;
            smaller = smaller.next;
        } else {
            bigger.next = head;
            bigger = bigger.next;
        }
        head = head.next;
    }
    smaller.next = biggerHead.next;
    bigger.next = null;
    return smallHead.next;
}

Example 9 with ListNode

use of com.pkumar7.datastructures.ListNode in project Data-Structures-Algorithms by pankajgangwar.

the class FebruaryW2 method reverseKGroupRec.

public ListNode reverseKGroupRec(ListNode head, int k) {
    ListNode fastPtr = head;
    int i = 0;
    for (; i < k && fastPtr != null; i++) {
        fastPtr = fastPtr.next;
    }
    if (i == k) {
        fastPtr = reverseKGroupRec(fastPtr, k);
        while (i-- > 0) {
            ListNode next = head.next;
            head.next = fastPtr;
            fastPtr = head;
            head = next;
        }
        head = fastPtr;
    }
    return head;
}

Example 10 with ListNode

use of com.pkumar7.datastructures.ListNode in project Data-Structures-Algorithms by pankajgangwar.

the class NovemberW3 method swapRecEasy.

public ListNode swapRecEasy(ListNode head) {
    if (head == null || head.next == null) {
        return head;
    }
    ListNode n = head.next;
    head.next = swapRecEasy(head.next.next);
    n.next = head;
    return n;
}