前缀和

长度最小的子数组

Find the minimal length of a subarray whose sum is greater than or equal to the target using efficient algorithms.

除了自身以外数组的乘积

Solve the 'Product of Array Except Self' problem by calculating the product of all elements except self for each index e…

区域和检索 - 数组不可变

The Range Sum Query - Immutable problem involves implementing a data structure to handle range sum queries efficiently.

二维区域和检索 - 矩阵不可变

Design a 2D matrix class that efficiently handles sum queries with O(1) time complexity using a prefix sum approach.

矩形区域不超过 K 的最大数值和

Solve the "Max Sum of Rectangle No Larger Than K" problem using binary search over the valid sum space to optimize space…

分割数组的最大值

Solve the 'Split Array Largest Sum' problem by minimizing the largest sum across k subarrays using dynamic programming a…

非重叠矩形中的随机点

Design an algorithm to pick random points within non-overlapping rectangles using binary search and reservoir sampling.

连续的子数组和

Identify if any continuous subarray sums to a multiple of k using prefix sums and hash table tracking efficiently.

连续数组

Find the maximum length contiguous subarray with equal numbers of 0s and 1s using array scanning and hash lookup efficie…

按权重随机选择

Random Pick with Weight requires implementing a probabilistic index picker using prefix sums and binary search efficient…

和为 K 的子数组

Count the total number of contiguous subarrays in an integer array that sum exactly to a target value k using optimized …

三个无重叠子数组的最大和

Maximize the sum of three non-overlapping subarrays with length k in an integer array using dynamic programming.

乘积小于 K 的子数组

Count subarrays with a product strictly less than a given value k using efficient algorithms like binary search and slid…

寻找数组的中心下标

Find the pivot index in an array where the sums of elements on both sides are equal using array and prefix sum technique…

我的日程安排表 II

Implement a calendar that allows double bookings but prevents triple bookings, managing overlapping intervals efficientl…

我的日程安排表 III

Implement My Calendar III to track maximum overlapping events efficiently using binary search and segment tree technique…

得分最高的最小轮调

Find the smallest rotation index with the highest score using array and prefix sum techniques.

最大平均值和的分组

Maximize the sum of averages by partitioning an integer array into at most k contiguous subarrays using dynamic programm…

字母移位

Given a string and a shift array, shift the first i+1 letters of the string as specified in the array.

和至少为 K 的最短子数组

Find the shortest subarray with a sum of at least k using binary search and sliding window techniques.

DI 序列的有效排列

The problem asks to find the number of valid permutations for a given DI sequence string using dynamic programming and s…

和相同的二元子数组

Count all contiguous subarrays in a binary array whose elements sum exactly to a given goal using prefix sums efficientl…

和可被 K 整除的子数组

Count the number of subarrays whose sum is divisible by a given integer k using array scanning and hash lookup.

K 连续位的最小翻转次数

Determine the minimum number of k-length consecutive bit flips needed to convert all zeros to ones in a binary array eff…