205 lines
6.4 KiB
Markdown
205 lines
6.4 KiB
Markdown
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---
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layout: page
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title: Review Problems
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---
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Let this be the list that you go thru for your review right before an upcoming interview. These problems provide the most bang for your buck.
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It is sorted by category. This list will continually change as your skill level progresses.
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#### Arrays (Two Pointers/Sliding Window)
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- [Sort Colors](/problems/sortColors)
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- [Water with Most Water](/problems/waterWithMostWater)
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- [Intersection of Two Arrays](/problems/intersectionOfTwoArrays2)
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- [Move Zeros](/problems/moveZeros)
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- [Remove Duplicates From Sorted Array](/problems/removeDupFromSortedArray)
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- [Three Sum](/problems/threeSum)
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#### HashTables
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- [Two Sum](/problems/twoSum)
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- [Group Isomorphic Strings](/problems/groupIsomorphicStrings)
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- [Isomorphic Strings](/problems/isomorphicStrings)
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#### Stacks
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Need more practice with stacks, don't assume they're easy
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- [Minimum Add to Make Parentheses Valid](/problems/minimumAddToMakeValidParenthesis)
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- [Valid Parenthesis]()
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#### Heap
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Whenever problem asks for kth largest or kth smallest. Think heap.
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- [Kth Largest Element in an Array](/problems/kthlargestElementInAnArray)
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- [Kth Largest Element in a Stream](/problems/kthlargestElementInAStream)
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- [Top Frequent K Elements](/problems/topFrequentKElements)
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#### Strings
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- [Longest Common Prefix](/problems/longestCommonPrefix)
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- [Longest Substring without Repeating Characters](/problems/longestSubstringWithoutRepeatingChars)
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- [Reverse Vowels from a String](/problems/reverseVowelsFromAString)
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- [Is Subsequence](/problems/isSubSequence)
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- [Longest Palindromic Substring](/problems/longestPalindromicSubstring)
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- [implement strstr](implement_strstr)
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#### Math
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- Reverse Integer
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#### Trees
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- [Deepest Leaves Sum BFS](/problems/deepestLeavesSumBFS)
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- [Deepest Leaves Sum DFS](/problems/deepestLeavesSumDFS)
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- [Validate BST](/problems/validateBST)
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- [LCA Binary Tree (No parent pointers)](/problems/lcaBinaryTree)
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- Easy Tree Problems
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- [Max Depth](/problems/maxDepth)
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- [Is Tree Balanced](/problems/isTreeBalanced)
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- [Is Same Tree](/problems/isSameTree)
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- [Is Symmetric Tree?](/problems/isSymmetricTree)
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- [Is Sub Tree](/problems/isSubtree)
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- [Invert/Reverse Tree](/problems/invertTree)
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#### Path Sums
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- [Path Sum](/problems/pathSum)
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- [Path Sum 2](/problems/pathSum2)
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- [Path Sum 3](/problems/pathSum3)
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#### BFS (Trees)
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- [Binary Tree Zig Zag](/problems/binaryTreeZigZag)
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- [Cousins in Binary Tree](/problems/cousinsInBinaryTree)
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#### DFS (Trees)
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- [Binary Tree Zig Zag](/problems/binaryTreeZigZagDfs)
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#### Binary Search
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Need to get way better at identifying and applying these.
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[Leetcode List](https://leetcode.com/tag/binary-search/)
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- [Binary Search](/problems/binarySearch)
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- [Guess Number Higher or Lower](/problems/guessNumberHigherOrLower)
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- [Find First and Last Position of Element in Sorted Array](/problems/searchForARange)
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- [Search Matrix](/problems/matrixSearch)
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- [Find Min in Sorted Array](/problems/findMinInSortedArray)
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- [Search in rotated array](/problems/searchInRotatedSortedArray)
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- [Search Rotated Array](/problems/searchRotatedArray)
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- [Arrange Coins](/problems/arrangeCoins)
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#### Bit Manipulation
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- [Missing Number](/problems/missingNumber)
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- [Single Number](/problems/singleNumber)
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- [Reverse Bits](/problems/reverseBits)
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- [Power(x,n)](/problems/powx-n)
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#### Interval
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- [Merge Interval](/problems/mergeIntervals)
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### Linked List
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Need to practice these. Keep messing up on edge cases. Learn when to use techniques like dummy nodes and prev pointers.
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Linked List Advice found [here](https://leetcode.com/explore/learn/card/linked-list/214/two-pointer-technique/1216/)
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- [Merge Sorted Lists](/problems/mergeSortedLLiter)
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- [Remove Nth Node from End of List](/problems/removeNthNodeFromEndOfList)
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- [Remove Linked List Elements](/problems/removeLinkedListElements)
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- [Reverse Linked List](/problems/reverseLLiterative)
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- Cycle Detection
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- [Linked List Cycle I](/problems/llcycle)
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- [Linked List Cycle II](/problems/llcycle2)
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- [Find the Duplicate number](/problems/findTheDuplicateNumber)
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- [Flatten Mutlilevel LInked List](/problems/flattenMultilevelDoublyLinkedList)
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- [Reorder List - list reversal and merge as subproblems](/problems/reorder_list)
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#### Matrix
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- [Rotate Image](/problems/rotateImage)
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- [Validate Sudoku](/problems/validateSudoku)
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- [Spiral Matrix](/problems/spiralMatrix)
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#### Dynamic Programming
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Can only solve these if seen before
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- [Longest Common Subsequence](/problems/longestCommonSubsequence)
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- [Unique Paths](/problems/uniquePaths)
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- [Coin Change](/problems/coinChange)
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- [Coin Change 2](/problems/coinChange2)
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- Perfect Squares
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- [Unique BST](/problems/uniqueBST)
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- Easy
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- [Buy and sell stock i](/problems/buyAndSellStock)
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- [Buy and sell stock 2](/problems/buyAndSellStock2)
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- [House robber 1](/problems/houseRobber)
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- [House robber 12](/problems/houseRobber2)
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- [max subarray](/problems/maxSubarray)
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- [max product subarray](/problems/maxProductSubarray)
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#### Recursion / Backtracking
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Solvable with backtracking template. Need to articulate them better.
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- [Permutation](/problems/permutations)
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- [Permutation (cascading)](/problems/permutationsCascading)
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- [Subsets](/problems/subsets)
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- [Subsets (cascading)](/problems/subsetsCascading)
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- [Generate Parenthesis](/problems/generateParanthesis)
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- [Combination Sum](/problems/combination_sum)
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- [Combination Sum II](/problems/combinationSum2)
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- [Combination Sum III](/problems/combinationSum3)
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[Check this link for combo sum 1,2,3 using add/pop method](https://leetcode.com/problems/combination-sum-ii/discuss/16878/Combination-Sum-I-II-and-III-Java-solution-(see-the-similarities-yourself))
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#### Islands
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Okay at solving these. Just need to remember pattern.
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- [Flood Fill](/problems/floodfill)
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- [Num Islands](/problems/numIslands)
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- [Max Area Of Islands](/problems/maxAreaOfIsland)
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- [Rotten Oranges](/problems/rottenOranges)
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- [Surrounded Region](/problems/surroundedRegion)
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- [Word Search](/problems/wordSearch)
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- [Island Perimeter](/problems/islandPerimeter)
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#### Graphs (Dijkstra)
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Just learning these. Do more of these problems to find patterns.
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- [All Paths Fro Source to Target](/problems/allPathsFromSourceToTarget)
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- Cheapest Flights
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- Network Delay Times
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- Reconstruct Iteranary
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#### Greedy
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Just learning these. Do more of these problems to find patterns.
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- [Queue Reconstruction By Height](/problems/queueReconstructionByHeight)
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- [Jump Game](/problems/jumpGame)
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