Solutions to leetcode problems

Problem	Solution
01 matrix	solution
2134 minimum swaps to group all 1s together ii	solution
3sum	solution
3sum closest	solution
a number after a double reversal	solution
add strings	solution
add two numbers	solution
all elements in two binary search trees	solution
all paths from source to target	solution
arithmetic slices	solution
array of doubled pairs	solution
backspace string compare	solution
balanced binary tree	solution
beautiful arrangement ii	solution
best time to buy and sell stock	solution
best time to buy and sell stock ii	solution
best time to buy and sell stock iii	solution
best time to buy and sell stock iv	solution
best time to buy and sell stock with cooldown	solution
binary search	solution
binary search tree iterator	solution
binary search tree to greater sum tree	solution
binary tree inorder traversal	solution
binary tree level order traversal	solution
binary tree level order traversal ii	solution
binary tree maximum path sum	solution
binary tree paths	solution
binary tree postorder traversal	solution
binary tree preorder traversal	solution
binary tree right side view	solution
binary tree tilt	solution
binary tree zigzag level order traversal	solution
bitwise ors of subarrays	solution
break a palindrome	solution
broken calculator	solution
buddy strings	solution
build an array with stack operations	solution
bulls and cows	solution
candy	solution
capitalize the title	solution
cells with odd values in a matrix	solution
check if a string can break another string	solution
check if all as appears before all bs	solution
check if all the integers in a range are covered	solution
check if every row and column contains all numbers	solution
check if it is a straight line	solution
check if numbers are ascending in a sentence	solution
cinema seat allocation	solution
circular permutation in binary representation	solution
climbing stairs	solution
clone graph	solution
coin change	solution
coin change 2	solution
combination sum	solution
combination sum ii	solution
compare version numbers	solution
complement of base 10 integer	solution
complex number multiplication	solution
construct binary search tree from preorder traversal	solution
construct binary tree from inorder and postorder traversal	solution
construct binary tree from preorder and inorder traversal	solution
container with most water	solution
contains duplicate	solution
contiguous array	solution
continuous subarray sum	solution
convert bst to greater tree	solution
convert sorted array to binary search tree	solution
convert sorted list to binary search tree	solution
copy list with random pointer	solution
count and say	solution
count complete tree nodes	solution
count good nodes in binary tree	solution
count number of homogenous substrings	solution
count number of nice subarrays	solution
count of smaller numbers after self	solution
count primes	solution
count servers that communicate	solution
count sorted vowel strings	solution
count square submatrices with all ones	solution
count the hidden sequences	solution
count triplets that can form two arrays of equal xor	solution
count vowels permutation	solution
count words obtained after adding a letter	solution
counting bits	solution
counting elements	solution
course schedule	solution
course schedule ii	solution
cousins in binary tree	solution
daily temperatures	solution
decode ways	solution
decoded string at index	solution
deepest leaves sum	solution
defanging an ip address	solution
delete node in a bst	solution
delete tree nodes	solution
destroying asteroids	solution
detect pattern of length m repeated k or more times	solution
determine if string halves are alike	solution
determine whether matrix can be obtained by rotation	solution
di string match	solution
diameter of binary tree	solution
distinct subsequences	solution
distinct subsequences ii	solution
distribute candies	solution
divisor game	solution
edit distance	solution
egg drop with 2 eggs and n floors	solution
execution of all suffix instructions staying in a grid	solution
fibonacci number	solution
find all anagrams in a string	solution
find all duplicates in an array	solution
find bottom left tree value	solution
find center of star graph	solution
find elements in a contaminated binary tree	solution
find k closest elements	solution
find k pairs with smallest sums	solution
find latest group of size m	solution
find longest awesome substring	solution
find median from data stream	solution
find minimum in rotated sorted array	solution
find pivot index	solution
find positive integer solution for a given equation	solution
find smallest letter greater than target	solution
find the duplicate number	solution
find the k beauty of a number	solution
find the kth smallest sum of a matrix with sorted rows	solution
find the longest substring containing vowels in even counts	solution
find the middle index in array	solution
find the smallest divisor given a threshold	solution
find the student that will replace the chalk	solution
find the town judge	solution
find winner on a tic tac toe game	solution
first bad version	solution
first missing positive	solution
first unique character in a string	solution
first unique number	solution
flatten a multilevel doubly linked list	solution
flatten binary tree to linked list	solution
flood fill	solution
gas station	solution
generate parentheses	solution
get maximum in generated array	solution
global and local inversions	solution
gray code	solution
greatest sum divisible by three	solution
grid game	solution
group anagrams	solution
group the people given the group size they belong to	solution
happy number	solution
hexspeak	solution
house robber	solution
house robber ii	solution
house robber iii	solution
image overlap	solution
implement queue using stacks	solution
implement stack using queues	solution
implement trie prefix tree	solution
insert delete getrandom o1	solution
insert into a binary search tree	solution
integer break	solution
integer replacement	solution
integer to roman	solution
interleaving string	solution
intersection of two arrays	solution
intersection of two arrays ii	solution
intersection of two linked lists	solution
interval list intersections	solution
intervals between identical elements	solution
invert binary tree	solution
is graph bipartite	solution
is subsequence	solution
island perimeter	solution
isomorphic strings	solution
iterator for combination	solution
jewels and stones	solution
jump game	solution
jump game ii	solution
jump game vi	solution
k closest points to origin	solution
k concatenation maximum sum	solution
k th symbol in grammar	solution
kids with the greatest number of candies	solution
kth largest element in an array	solution
kth smallest element in a bst	solution
kth smallest element in a sorted matrix	solution
largest magic square	solution
largest plus sign	solution
largest rectangle in histogram	solution
largest time for given digits	solution
last stone weight	solution
leftmost column with at least a one	solution
length of last word	solution
letter case permutation	solution
letter combinations of a phone number	solution
linked list cycle	solution
linked list cycle ii	solution
long pressed name	solution
longest common prefix	solution
longest common subsequence	solution
longest consecutive sequence	solution
longest harmonious subsequence	solution
longest increasing subsequence	solution
longest palindrome by concatenating two letter words	solution
longest palindromic subsequence	solution
longest palindromic substring	solution
longest repeating character replacement	solution
longest substring without repeating characters	solution
longest valid parentheses	solution
longest word in dictionary through deleting	solution
lowest common ancestor of a binary search tree	solution
lowest common ancestor of a binary tree	solution
lru cache	solution
majority element	solution
majority element ii	solution
matrix block sum	solution
max consecutive ones	solution
max consecutive ones iii	solution
max difference you can get from changing an integer	solution
max points on a line	solution
maximal rectangle	solution
maximal square	solution
maximize sum of array after k negations	solution
maximum depth of binary tree	solution
maximum difference between increasing elements	solution
maximum frequency stack	solution
maximum height by stacking cuboids	solution
maximum length of a concatenated string with unique characters	solution
maximum length of subarray with positive product	solution
maximum level sum of a binary tree	solution
maximum non negative product in a matrix	solution
maximum number of balloons	solution
maximum number of coins you can get	solution
maximum number of removable characters	solution
maximum number of weeks for which you can work	solution
maximum number of words found in sentences	solution
maximum product subarray	solution
maximum profit in job scheduling	solution
maximum score of a good subarray	solution
maximum subarray	solution
maximum sum circular subarray	solution
maximum twin sum of a linked list	solution
maximum white tiles covered by a carpet	solution
median of two sorted arrays	solution
merge in between linked lists	solution
merge intervals	solution
merge k sorted lists	solution
merge sorted array	solution
merge triplets to form target triplet	solution
merge two sorted lists	solution
middle of the linked list	solution
min cost climbing stairs	solution
min stack	solution
minimized maximum of products distributed to any store	solution
minimum changes to make alternating binary string	solution
minimum cost of buying candies with discount	solution
minimum deletions to make character frequencies unique	solution
minimum depth of binary tree	solution
minimum insertion steps to make a string palindrome	solution
minimum limit of balls in a bag	solution
minimum number of arrows to burst balloons	solution
minimum number of people to teach	solution
minimum number of removals to make mountain array	solution
minimum number of vertices to reach all nodes	solution
minimum path sum	solution
minimum remove to make valid parentheses	solution
minimum swaps to group all 1s together ii	solution
minimum swaps to make strings equal	solution
minimum time to collect all apples in a tree	solution
minimum time to make rope colorful	solution
minimum time visiting all points	solution
minimum value to get positive step by step sum	solution
minimum window substring	solution
missing number	solution
most common word	solution
most visited sector in a circular track	solution
move zeroes	solution
n queens	solution
n th tribonacci number	solution
next greater element i	solution
next greater element ii	solution
next greater element iii	solution
next permutation	solution
number complement	solution
number of burgers with no waste of ingredients	solution
number of closed islands	solution
number of dice rolls with target sum	solution
number of enclaves	solution
number of islands	solution
number of laser beams in a bank	solution
number of matching subsequences	solution
number of steps to reduce a number to zero	solution
number of sub arrays with odd sum	solution
number of ways to split array	solution
number of ways to stay in the same place after some steps	solution
number of ways where square of number is equal to product of two numbers	solution
online stock span	solution
palindrome linked list	solution
palindrome number	solution
palindrome partitioning	solution
palindrome partitioning ii	solution
palindrome partitioning iii	solution
partition array for maximum sum	solution
partition array into disjoint intervals	solution
partition array into three parts with equal sum	solution
partition equal subset sum	solution
partition labels	solution
partition list	solution
pascals triangle	solution
pascals triangle ii	solution
path sum	solution
path sum ii	solution
path sum iii	solution
perfect squares	solution
perform string shifts	solution
permutation sequence	solution
permutations	solution
plus one	solution
populating next right pointers in each node	solution
populating next right pointers in each node ii	solution
powx n	solution
prison cells after n days	solution
process tasks using servers	solution
product of array except self	solution
queens that can attack the king	solution
range addition ii	solution
range sum of bst	solution
range sum query 2d immutable	solution
range sum query immutable	solution
range sum query mutable	solution
ransom note	solution
reconstruct a 2 row binary matrix	solution
recover binary search tree	solution
redistribute characters to make all strings equal	solution
reducing dishes	solution
redundant connection	solution
redundant connection ii	solution
regular expression matching	solution
relative sort array	solution
remove all adjacent duplicates in string	solution
remove duplicates from sorted array	solution
remove duplicates from sorted array ii	solution
remove duplicates from sorted list	solution
remove duplicates from sorted list ii	solution
remove element	solution
remove interval	solution
remove nth node from end of list	solution
remove palindromic subsequences	solution
remove sub folders from the filesystem	solution
reordered power of 2	solution
reorganize string	solution
replace all s to avoid consecutive repeating characters	solution
replace the substring for balanced string	solution
reverse integer	solution
reverse linked list	solution
reverse linked list ii	solution
reverse nodes in k group	solution
reverse only letters	solution
reverse words in a string	solution
rotate array	solution
rotate image	solution
rotate list	solution
rotting oranges	solution
running sum of 1d array	solution
same tree	solution
scramble string	solution
search a 2d matrix	solution
search a 2d matrix ii	solution
search in a binary search tree	solution
search in rotated sorted array	solution
search in rotated sorted array ii	solution
search insert position	solution
search suggestions system	solution
serialize and deserialize binary tree	solution
serialize and deserialize bst	solution
set matrix zeroes	solution
shift 2d grid	solution
shifting letters	solution
shortest distance to a character	solution
shortest path in binary matrix	solution
shortest unsorted continuous subarray	solution
shuffle the array	solution
simple bank system	solution
simplify path	solution
single element in a sorted array	solution
single number	solution
sliding window maximum	solution
slowest key	solution
smallest integer divisible by k	solution
sort an array	solution
sort array by parity ii	solution
sort characters by frequency	solution
sort colors	solution
sort integers by the power value	solution
spiral matrix	solution
spiral matrix ii	solution
split a string in balanced strings	solution
split linked list in parts	solution
sqrtx	solution
stone game	solution
string to integer atoi	solution
subarray sum equals k	solution
subsets	solution
subsets ii	solution
subtract the product and sum of digits of an integer	solution
sudoku solver	solution
sum of left leaves	solution
sum of root to leaf binary numbers	solution
sum of square numbers	solution
sum root to leaf numbers	solution
super egg drop	solution
super ugly number	solution
swap nodes in pairs	solution
swim in rising water	solution
symmetric tree	solution
target sum	solution
the k weakest rows in a matrix	solution
thousand separator	solution
three divisors	solution
trapping rain water	solution
triangle	solution
two sum	solution
two sum ii input array is sorted	solution
two sum iv input is a bst	solution
unique binary search trees	solution
unique binary search trees ii	solution
unique email addresses	solution
unique paths	solution
unique paths ii	solution
valid anagram	solution
valid palindrome	solution
valid palindrome ii	solution
valid parentheses	solution
valid parenthesis string	solution
valid perfect square	solution
valid sudoku	solution
valid triangle number	solution
validate binary search tree	solution
verify preorder serialization of a binary tree	solution
vowels of all substrings	solution
wildcard matching	solution
word break	solution
word break ii	solution
word pattern	solution
zigzag conversion	solution