prefix sum

Minimum Size Subarray Sum

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

Product of Array Except Self

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

Range Sum Query - Immutable

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

Range Sum Query 2D - Immutable

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

Max Sum of Rectangle No Larger Than K

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

Split Array Largest Sum

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

Random Point in Non-overlapping Rectangles

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

Continuous Subarray Sum

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

Contiguous Array

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

Random Pick with Weight

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

Subarray Sum Equals K

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

Maximum Sum of 3 Non-Overlapping Subarrays

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

Subarray Product Less Than K

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

Find Pivot Index

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

My Calendar II

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

My Calendar III

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

Smallest Rotation with Highest Score

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

Largest Sum of Averages

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

Shifting Letters

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

Shortest Subarray with Sum at Least K

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

Valid Permutations for DI Sequence

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

Binary Subarrays With Sum

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

Subarray Sums Divisible by K

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

Minimum Number of K Consecutive Bit Flips

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