Array String Hash Map Sliding Window Intermediate Implement the longestSubstringAtMostKDistinctLength method that returns the longest substring length with at most k distinct characters. Solved
Tree Binary Tree Binary Search Tree Breadth First Search Depth First Search Intermediate Implement the sumRootToLeafNumbers method that returns the sum of all root-to-leaf numbers in a binary tree. Solved
Tree Binary Tree Binary Search Tree Breadth First Search Depth First Search Intermediate Implement the countGoodNodesBinaryTree method that counts good nodes in a binary tree. Solved
Tree Binary Tree Binary Search Tree Breadth First Search Depth First Search Intermediate Implement the symmetricBinaryTreeCheck method that checks whether a binary tree is a mirror of itself. Solved
Array Sorting Binary Search Proficient Implement the shipPackagesWithinDaysCapacity method that returns the minimum ship capacity needed to deliver packages within given days. Solved
Array Sorting Binary Search Intermediate Implement the smallestDivisorUnderThreshold method that finds the smallest divisor satisfying a threshold condition. Solved
Array Sorting Binary Search Intermediate Implement the kthMissingPositiveNumber method that returns the kth missing positive integer from a sorted array. Solved
String Manipulation String Intermediate Implement the multiplyLargeNumbersString method that multiplies two non-negative integers represented as strings. Solved
Stack Topological Sort Simulation Proficient Implement the removeDuplicateLettersSmallest method that removes duplicate letters and returns the smallest possible result. Solved
Stack Topological Sort Simulation Proficient Implement the longestValidParenthesesLength method that returns the length of the longest valid parentheses substring. Solved
Array Matrix Breadth First Search Guru Implement the maximalRectangleArea method that returns the largest rectangle of ones in a binary matrix. Solved
Array Matrix Breadth First Search Proficient Implement the surroundedRegionsSafeCount method that counts cells not captured in a surrounded-regions board. Solved
Array Matrix Breadth First Search Intermediate Implement the nearestZeroDistanceSum method that returns the sum of distances from every cell to its nearest zero. Solved
Graph Breadth First Search Depth First Search Shortest Path Minimum Spanning Tree Proficient Implement the minimumEffortPathGrid method that returns the minimum effort required to travel across a height grid. Solved
Graph Breadth First Search Depth First Search Shortest Path Minimum Spanning Tree Intermediate Implement the countProvincesUnionFind method that counts connected city groups from an adjacency matrix. Solved
Graph Breadth First Search Depth First Search Shortest Path Minimum Spanning Tree Proficient Implement the findRedundantConnection method that returns the edge that creates a cycle in an undirected graph. Solved
Graph Breadth First Search Depth First Search Shortest Path Minimum Spanning Tree Proficient Implement the cheapestFlightWithinKStops method that finds the cheapest price from source to destination within a stop limit. Solved
Math Dynamic Programming Guru Implement the burstBalloonsMaxCoins method that returns the maximum coins obtainable by bursting balloons in the best order. Solved
Math Dynamic Programming Proficient Implement the maxProfitWithCooldown method that returns the maximum stock profit with a one-day cooldown after selling. Solved