Programmer Think

1. Find the 3-bit even number Give you an integer array digits, where each element is a number (0 - 9). There may be duplicate elements in the array. You need to find all integers that meet the following conditions and are different from each other: The integer consists of three elements in digits connected in any order. The integer does not co ...

1, LeetCode 21. Merge two ordered linked lists Method 1: iteration Code and performance class Solution { public ListNode mergeTwoLists(ListNode l1, ListNode l2) { ListNode dummy = new ListNode(-1); ListNode p = dummy; ListNode p1 = l1; ListNode p2 = l2; while(p1 != null && p2 != null){ ...

This paper summarizes some basic operations of chained binary tree in class, including Calculate the number of nodes of the binary treeCalculate the number of leaf nodes of binary treeCalculate the number of nodes in the K-th layer of the binary treeCalculate the depth / height of the binary treeFind and return the node with the value of x ...

If the hash value corresponding to the element at the index position is the same as the hash value of the element to be inserted, and it is the same reference or content, it cannot be added If the index position has a value and satisfies a red black tree, call the algorithm of the red black tree to add If the index position has a value and i ...

1, Modern writing implementation interface The first is the realization of modern writing method of copy construction: string_str(const string_str& st) :str(nullptr) { string_str tem(st.str); swap(this->str, tem.str); First, set this - > STR to null, then temp calls the constructor and initializes this - > STR wit ...

chart In mathematics, a graph is a structure described in a group of objects, some of which are "related" in a sense. These objects correspond to mathematical abstractions called vertices (also known as nodes or points), and each associated vertex pair is called an edge (also known as a link or line). Usually, a graph is depicted ...

  There are several questions about set: (1) Why is the insertion and deletion efficiency of map and set higher than that of other sequence containers? Most people say that it is very simple, because there is no need to copy and move memory for associated containers. Yes, indeed. All elements in the set container are stored in the form o ...

More algorithm solutions, please pay attention to the official account, "programmer"Sorting of single linked listProblem descriptionLeetCode 148. Sorting linked listGiven an unordered single linked list with n nodes, it is sorted in ascending order.Requirements: space complexity O(n), time complexity O(nlogn).Example:Input: [- 1,0, - ...

1 Introduction Differences between HashMap before and after Java 8: Contrast ItemBefore Java 8After Java 8 (including)Node typeEntryNode/TreeNodestorage structureArray + One-way Chain ListArray + One-way Chain List / Red-Black TreeInsertion methodHead InterpolationTail interpolationExpansion timingExpand before insertingInsert before expandha ...

Set framework generalization A collection can be regarded as a container for storing object information. Some excellent algorithms and data structures are encapsulated in the collection framework of Java. The Collection interface stores a set of non unique and unordered objectsThe List interface stores a set of non unique and ordered obje ...