随笔分类 - leetcode
[Leetcode 543]二叉树的直径Diameter of Binary Tree
摘要：题目 二叉树的直径，即是求树中任意俩点间的最大距离（深度） Given the root of a binary tree, return the length of the diameter of the tree. The diameter of a binary tree is the len
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[Leetcode 19]删除链表中倒数第N个元素Remove Nth Node From End of List
摘要：题目 删除链表head中倒数第N个元素 Given the head of a linked list, remove the nth node from the end of the list and return its head. Example 1: Input: head = [1,2,3
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[模板]删除重复值leetcode26/27/80/283
摘要：不消耗额外空间的前提下，将数字向前移向。 https://www.bilibili.com/video/BV1Pv4y1Z76N
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[Leetcode 152]最大乘积子串Maximum Product Subarray 踩坑
摘要：【题目】 一串int数组中找到乘积最大的子串，子串必须连续，返回成绩ans Given an integer array nums, find a contiguous non-empty subarray within the array that has the largest product,
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[Leetcode 445]正序链表相加Add Two Numbers II
摘要：【题目】 将链表组成的数相加 leetcode2变式，2题是高位在后，现在是高位在前节点 You are given two non-empty linked lists representing two non-negative integers. The most significant dig
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[Leetcode 206]反转链表Reverse Linked List
摘要：【题目】 反转链表是之后很多题的基础 把链表12345反转成54321 Given the head of a singly linked list, reverse the list, and return the reversed list. Example 1: Input: head = [
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[Leetcode 2]两数相加链表Add Two Numbers
摘要：【题目】 将两个用list存储的数字相加，返回相加后的值 You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order,
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[Leetcode 44]合并有序列表Merge k Sorted Lists
摘要：【题目】 将两个有序链表合并成一个有序链表 Merge two sorted linked lists and return it as a sorted list. The list should be made by splicing together the nodes of the firs
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[Leetcode 11]容器中装最多的水Container With Most Water
摘要：【题目】 木桶短板，能装的最多水，由最短的那条决定 Given n non-negative integers a1, a2, ..., an , where each represents a point at coordinate (i, ai). n vertical lines are dr
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[整理]K sum系列问题 N数之和 多指针模板 leetcode15/16/18/167/259/454
摘要：【整体思路】 先Arrays.sort()排序，不然后续指针没法用 对于K数之和，固定K-2个指针（循环），再用两指针一头一尾，根据sum大了小了，调左或调右 4数之和，2固定2移动； 3数之和，1固定2移动； 一定要记得去重，不仅为了减少工作量，也是确保输出结果的唯一 【题目】 leetcode1
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[Leetcode 781]森林中的兔子 Rabbits in Forest 巧妙
摘要：【题目】 问每只兔子，有多少只和你颜色相同的（颜色问全了，不一定问道每只兔子），求这片森林中至少有多少只兔子 There is a forest with an unknown number of rabbits. We asked n rabbits "How many rabbits have
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[Leetcode 26/27/80/283/977]移除(重复)元素 指针专题整理
摘要：【总结】 参考https://www.bilibili.com/video/BV1Pv4y1Z76N 适用情况：大部分需数组升序 【代码】 27 移除元素 不用管移除后半部分是否为正确答案，所以可直接nums[flag]=nums[i] class Solution { public int rem
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[Leetcode 88]合并有序数组Merge Sorted Array 归并排序
摘要：【题目】 合并两个数组，两个数组已分别顺序排好，不能使用额外数组，就存在nums1中 You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n,
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[Leetcode 44]合并有序列表Merge k Sorted Lists
摘要：【题目】 找到第一个没有重复出现的字母 Given a string s, find the first non-repeating character in it and return its index. If it does not exist, return -1. Example 1: I
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[Leetcode 198/213/337]强盗偷家 House Robber 三题DP整理
摘要：【题目1】 此系列有三题，都是强盗偷家不能偷相邻邻居，否则会被发现。问最多能偷多少钱 You are a professional robber planning to rob houses along a street. Each house has a certain amount of mon
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[Leetcode 162]爬楼梯最小耗费Min Cost Climbing Stairs**
摘要：【题目】 爬楼梯变式，可以上1/2台阶，每个台阶有cost，求爬上去的最小耗费 You are given an integer array cost where cost[i] is the cost of ith step on a staircase. Once you pay the cos
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[Leetcode 162]寻找峰值 Find Peak Element**
摘要：【题目】 寻找峰值返回坐标，比左右都大，时间复杂度必须是 O(log n) A peak element is an element that is strictly greater than its neighbors. Given an integer array nums, find a pe
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[Leetcode 152]旋转数组中找到最小值Find Minimum in Rotated Sorted Array
摘要：【题目】 说了一堆就是在旋转后的顺序数组中找最小值，时间复杂度必须是 O(log n) Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the
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[Leetcode 718]最长重复子数列Maximum Length of Repeated Subarray
摘要：【题目】 两个数组，求他们最长的相同子串长度，数组长度不一定相同 Given two integer arrays nums1 and nums2, return the maximum length of a subarray that appears in both arrays. Exampl
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