LeetCode topic classification and interview questions collation

Subject category

Hash related

• [q1_sum of two numbers](/src/hash related/q1_sum of two numbers)
• [q387_the first unique character in the string] (/src/hash related/q387_ the first unique character in the string)

Linked list operation

• [q2_Add two numbers](/src/Link list operation/q2_Add two numbers)
• [q19_delete the Nth node from the bottom of the linked list](/src/list operation/q19_delete the Nth node from the bottom of the linked list)
• [q25_k set of flipped linked lists] (/src/linked list operation/q25_k set of flipped linked lists)
• [q61_rotating linked list](/src/linked list operation/q61_rotating linked list)
• [q138_copy linked list with random pointer](/src/linked list operation/q138_copy linked list with random pointer)
• [q206_reverse linked list](/src/linked list operation/q206_reverse linked list)

Double pointer traversal/sliding window

• [q3_Longest substring without repeated characters] (/src/Double pointer traversal/q3_Longest substring without repeated characters)
• [q11_Container with the most water](/src/Double pointer traversal/q11_Container with the most water)
• [q15_sum of three numbers](/src/double pointer traversal/q15_sum of three numbers)
• [q16_closest sum of three numbers](/src/dual pointer traversal/q16_closest sum of three numbers)
• [q26_delete duplicates in the sorted array](/src/double pointer traversal/q26_delete duplicates in the sorted array)
• [q42_trapping-rain-water](/src/Dual pointer traversal/q42_接雨水)
• [q121_The best time to buy and sell stocks] (/src/Dual pointer traversal/q121_The best time to buy and sell stocks)
• [q209_The smallest length sub-array](/src/Double pointer traversal/q209_The smallest length sub-array)

Fast and slow pointer traversal

• [q141_circular linked list](/src/fast and slow pointer traversal/q141_circular linked list)
• [q202_happy number](/src/speed pointer traversal/q202_happy number)
• [q876_intermediate node of linked list] (/src/fast/slow pointer traversal/q876_intermediate node of linked list)

Interval merge

• [q56_Merge interval](/src/Merge interval/q56_Merge interval)

String manipulation

• [q6_Zigzag transformation](/src/String operation/q6_Zigzag transformation)
• [q14_longest common prefix](/src/string operation/q14_longest common prefix)
• [q763_Dividing letter interval](/src/String operation/q763_Dividing letter interval)

Digital operation

• [q7_integer inversion](/src/digital operation/q7_integer inversion)
• [q8_string conversion integer](/src/number operation/q8_string conversion integer)
• [q9_Palindrome Number](/src/Number Operation/q9_Palindrome Number)
• [q43_string multiplication](/src/number operation/q43_string multiplication)
• [q172_zero after factorial](/src/digital operation/q172_zero after factorial)
• [q258_Add everybody](/src/Digital operation/q258_Add everybody)

Array operations

• [q54_spiral matrix](/src/array operation/q54_spiral matrix)
• [q73_Zero Matrix](/src/Array Operation/q73_Zero Matrix)
• [q78_subset](/src/array operation/q78_subset)
• [q384_scrambling array](/src/array operation/q384_scrambling array)
• [q581_shortest unordered continuous subarray](/src/array operation/q581_shortest unordered continuous subarray)
• [q945_Minimum increment to make the array unique] (/src/Array operation/q945_Minimum increment to make the array unique)

Stack related

• [q20_valid brackets](/src/stack related/q20_valid brackets)
• [q32_longest valid bracket](/src/stack related/q32_longest valid bracket)
• [q155_Minimal stack](/src/stack related/q155_Minimal stack)
• [q224_basic calculator](/src/stack related/q224_basic calculator)
• [q232_implement queue with stack](/src/stack related/q232_implement queue with stack)
• [q316_remove duplicate letters](/src/stack related/q316_remove duplicate letters)

Heap related

• [q215_the Kth largest element in the array] (/src/heap-related/q215_the Kth largest element in the array)
• [q347_top K high frequency elements](/src/heap related/q347_top K high frequency elements)

Recursion

• [q21_merge two ordered linked lists](/src/recursion/q21_merge two ordered linked lists)
• [q101_symmetric binary tree](/src/recursion/q101_symmetric binary tree)
• [q104_Maximum Depth of Binary Tree](/src/Recursion/q104_Maximum Depth of Binary Tree)
• [q226_flip binary tree](/src/recursion/q226_flip binary tree)
• [q236_The nearest common ancestor of the binary tree](/src/recursion/q236_The nearest common ancestor of the binary tree)

Divide and Conquer/Dichotomy

-[q23_Merge K sorted lists](/src/divide and conquer/q23_Merge K sorted lists) -[q33_Search rotating sorted array](/src/divide and conquer/q33_search rotating sorted array) -[q34_Find the first and last position of an element in the sorted array](/src/divide and conquer/q34_Find the first and last position of an element in the sorted array)

Dynamic Planning

-[q5_longest palindrome substring](/src/dynamic programming/q5longest palindrome substring) -[q53_Maximum Subsequence Sum](/src/Dynamic Programming/q53_Max Subsequence Sum) -[q62_different path](/src/dynamic programming/q62_different path) -[q64_Minimum path sum](/src/dynamic programming/q64_Minimum path sum) -[q70_stair climbing](/src/dynamic programming/q70_stair climbing) -[q118_杨辉 Triangle](/src/Dynamic Programming/q118杨辉 Triangle) -[q300_Longest Ascending Subsequence](/src/Dynamic Programming/q300_Longest Ascending Subsequence) -[q1143_longest common subsequence](/src/dynamic programming/q1143_longest common subsequence) -[q1277_square submatrix with all 1s](/src/dynamic programming/q1277_square submatrix with all 1s)

Backtracking

-[q10_regular expression matching](/src/backtracking/q10_regular expression matching) -[q22_bracket generation](/src/backtracking/q22_bracket generation) -[q40_combined sum 2](/src/backtracking/q40_combined sum 2) -[q46_all permutation](/src/backtracking/q46_all permutation)

Tree traversal

-[q94_In-order traversal of binary tree](/src/Tree traversal/q94_In-order traversal of binary tree) -[q102_Binary tree traversal](/src/Tree traversal/q102_Binary tree traversal) -[q110_balanced binary tree](/src/tree traversal/q110_balanced binary tree) -[q144_Preorder traversal of binary tree](/src/Tree traversal/q144_Preorder traversal of binary tree) -[q145_Post-order traversal of binary tree](/src/Traversal of tree/q145_Post-order traversal of binary tree)

Binary search tree related

-[q98_Verify Binary Search Tree](/src/Binary Search Tree Related/q98_Verify Binary Search Tree) -[q450_delete nodes in binary search tree](/src/binary search tree related/q450_delete nodes in binary search tree) -[q701_insert operation in binary search tree](/src/binary search tree related/q701_insert operation in binary search tree)

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Interview questions finishing

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