Programmer Think

1. Delete all nodes in the linked list equal to the given value val OJ link class Solution { public ListNode removeElements(ListNode head, int val) { if(head==null){ return null; } ListNode prev=head; ListNode cur=head.next; while(cur!=null){ if(cur.val==val){ ...

A The input includes two positive integers a, B (1 < = a, B < = 10 ^ 9), and the input data includes multiple groups. Output Description: Output the result of a+b Example 1 input 1 5 10 20 output 6 30 import java.util.Scanner; public class Main1 { public static void main(String[] args) { Scanner sc = new Scanner(System.in); ...

preface Queue is a "first in, first out" linear table. Only one end of the table is inserted (queued), which is called the end of the queue, and the other end is deleted (queued), which is called the opposite end, that is, "tail in, head out". Only the head and tail of the queue can be accessed by the outside world, s ...

Basic data structure - stack Stack is a last in, first out linear table. It is the most basic data structure and has applications in many places. What is stack Stack is a linear table that restricts insertion and deletion to only one location. Among them, the end that allows insertion and deletion is located at the end of the table, which is ...

2, Binary tree 1. Definition of binary tree A binary tree is a tree structure in which each node has at most two subtrees. It has five basic forms: binary tree can be an empty set; The root can have an empty left subtree or right subtree; Or the left and right subtrees are empty. 2. Properties of binary tree Property 1: the maximum number ...

1. DS stack - output in reverse order (used by STL stack) Title Description C + + has its own stack object stack, so there is no need to write the specific implementation code of stack operation. This topic mainly helps you to be familiar with the use of stack object, and then realize the reverse order output of string Enter a string, p ...