双·指针·invariant模式

盛最多水的容器

Find two vertical lines that can form a container with the most water in a given array of heights.

三数之和

Given an integer array, return all unique triplets where the sum is zero using two-pointer scanning with careful duplica…

最接近的三数之和

Find the sum of three integers in an array that is closest to a given target using two-pointer scanning.

四数之和

The 4Sum problem requires finding all unique quadruplets in an array that sum to a specific target value.

删除有序数组中的重复项

Learn how to remove duplicates from a sorted array in-place using two-pointer scanning while preserving element order.

移除元素

Remove Element challenges you to remove a value from an array in-place using efficient two-pointer scanning and tracking…

找出字符串中第一个匹配项的下标

Locate the first occurrence of a substring within a string using a two-pointer scanning strategy and invariant tracking …

下一个排列

Next Permutation is a medium-difficulty problem focusing on generating the next lexicographically greater permutation of…

颜色分类

Sort Colors requires in-place reordering of an array using a two-pointer scanning strategy to group 0s, 1s, and 2s effic…

删除有序数组中的重复项 II

Solve the problem of removing duplicates from a sorted array in-place, ensuring each element appears at most twice, usin…

合并两个有序数组

Merge two sorted arrays into the first array in non-decreasing order, using a two-pointer approach.

验证回文串

Check if a given string is a valid palindrome by using two-pointer scanning and invariant tracking techniques.

反转字符串中的单词

Reverse Words in a String requires reordering words using precise two-pointer scanning with careful space handling for e…

比较版本号

Compare two version numbers by checking their individual revisions, considering missing revisions as zero, using a two-p…

轮转数组

Rotate Array challenges you to shift elements right by k steps using precise two-pointer scanning and invariant tracking…

快乐数

Determine if a number is happy by repeatedly summing squares of digits using two-pointer scanning to detect cycles effic…

移动零

Move all zeros in an array to the end while preserving the order of non-zero elements using efficient in-place operation…

数据流的中位数

Implement a MedianFinder class that supports adding numbers and finding the median from a data stream.

拼接最大数

Create Maximum Number involves merging digits from two arrays while preserving order, maximizing the resulting number.

反转字符串

Reverse a character array in-place using a two-pointer scanning technique, ensuring minimal memory and correct index swa…

反转字符串中的元音字母

Reverse Vowels of a String uses a two-pointer approach to reverse the vowels in a string while leaving the consonants in…

压缩字符串

Compress a character array in-place by converting consecutive repeated characters into counts using two-pointer scanning…

分发饼干

Maximize content children by assigning at most one cookie per child using two-pointer scanning and greedy sorting techni…

神奇字符串

Count the number of '1's in the first n characters of a magical string using two-pointer scanning and invariant tracking…