带头结点。 /*** Definition for singly-linked list.* public class ListNode {* int val;* ListNode next;* ListNode(int x) { val = x; }* }*/public class Solution {public ListNode swapPairs(L
很久以前,我在使用lua的过程中,对于pairs和ipairs的理解还处于表层,认为我了解的就是全部。 ipairs就是对表中元素进行顺序排序,pairs就是对表中元素进行随机排序。 比如如下例子: local t = {20, "ss", print, 10}print("------ipairs------")for k,v in ipairs(t) doprint(k,v)end
time limit per test 2 seconds memory limit per test 256 megabytes You are given an array a1,a2,…,ana1,a2,…,an consisting of nn distinct integers. Count the number of pairs of indices (i,j)(i,j) su
题目:swap nodes in pairs <span style="font-size:18px;">/*** LeetCode Swap Nodes in Pairs * 题目:输入一个链表,要求将链表每相邻的两个节点交换位置后输出* 思路:遍历一遍即可,时间复杂度O(n)* Definition for singly-linked list.* public class ListNo
问题描述: Given an array of integers and an integer k, you need to find the number of unique k-diff pairs in the array. Here a k-diff pair is defined as an integer pair (i, j), where i and j are both num
问题描述: Implement a MapSum class with insert, and sum methods. For the method insert, you'll be given a pair of (string, integer). The string represents the key and the integer represents the valu
Number of Pairs 题面翻译 【题目描述】 给出一个由整数组成的数组 a a a,求一对整数 ( i , j ) (i, j) (i,j)( 1 ≤ i < j ≤ n 1 \le i < j \le n 1≤i<j≤n)满足 l ≤ a i + a j ≤ r l \le a_i + a_j \le r l≤ai+aj≤r 的数量。 【输入格式】 在输入的第一行为
题目: Given a linked list, swap every two adjacent nodes and return its head. For example, Given 1->2->3->4, you should return the list as 2->1->4->3. Your algorithm should use only constant space.
好久没更LeetCode了,因为最近手头的事情比较多。今天更新两条easy问题。 1013. Pairs of Songs With Total Durations Divisible by 60 这个问题是一个模算术问题。将歌曲时长转为[0,59]余数即可。 class Solution {public int numPairsDivisibleBy60(int[] time) {int
Problem Description Chika gives you an integer sequence a1,a2,…,an and m tasks. For each task, you need to answer the number of “friendly pairs” in a given interval. friendly pair: for two integers a
题目都很短就懒得写题意了。 思路: 把每个字符的后缀都用hash表示然后用map存起来算数目。 统计的时候,对于当前的前缀我们可以算出其在后缀中出现的次数。 但问题是这样可能有重复。 解决办法是: c n t [ n e x t [ i ] ] − = c n t [ i ] cnt[next[i]] -= cnt[i] cnt[next[i]]−=cnt[i] 因为假设p1是p2的最长公共
题目描述 Given a linked list, swap every two adjacent nodes and return its head. Example: Given 1->2->3->4, you should return the list as 2->1->4->3. Note: Your algorithm should use only constant extr
Given a list of unique words. Find all pairs of distinct indices (i, j) in the given list, so that the concatenation of the two words, i.e. words[i] + words[j] is a palindrome. Example 1: Given wor
This way 文章目录 题意:AC自动机:广义后缀自动机: 题意: 给你n个字符串,任意选两个字符串,答案加上前一个字符串前缀和后一个字符串的后缀最长相同的部分长度的平方。问你答案是多少 AC自动机: 想练一下AC自动机,就用这个写了,有时间的话再用广义后缀自动机写一下。 首先我们肯定是要枚举所有的字符串,问题是将它当做前缀还是后缀。把当前的字符串当成后缀的话,你的fai
原题: D. The Number of Pairs time limit per test 2 seconds memory limit per test 512 megabytes input standard input output standard output You are given three positive (greater than zero) integers c, d