59 |
spiral matrix ii |
Arrays |
750 |
number of corner rectangles |
Arrays |
764 |
largest plus sign |
Arrays |
908 |
smallest range i |
Arrays |
922 |
sort array by parity ii |
Arrays |
1031 |
maximum sum of two non overlapping subarrays |
Arrays |
1385 |
find the distance value between two arrays |
Arrays |
1441 |
build an array with stack operations |
Arrays |
1292 |
maximum side length of a square with sum less than or equal to threshold |
Arrays Binary Search |
5 |
longest palindromic substring |
Binary Search |
275 |
h index ii |
Binary Search |
483 |
smallest good base |
Binary Search |
718 |
maximum length of repeated subarray |
Binary Search |
825 |
friends of appropriate ages |
Binary Search |
1095 |
find in mountain array |
Binary Search |
1283 |
find the smallest divisor given a threshold |
Binary Search |
1428 |
leftmost column with at least a one |
Binary Search |
1618 |
maximum font to fit a sentence in a screen |
Binary Search |
99 |
recover binary search tree |
Binary Search Trees (BST) |
510 |
inorder successor in bst ii |
Binary Search Trees (BST) |
1146 |
snapshot array |
Binary Search Design Data Structure |
508 |
most frequent subtree sum |
Binary Trees |
814 |
binary tree pruning |
Binary Trees |
1022 |
sum of root to leaf binary numbers |
Binary Trees |
1080 |
insufficient nodes in root to leaf paths |
Binary Trees |
1379 |
find a corresponding node of a binary tree in a clone of that tree |
Binary Trees |
1430 |
check if a string is a valid sequence from root to leaves path in a binary tree |
Binary Trees |
1318 |
minimum flips to make a or b equal to c |
Bit Manipulation |
568 |
maximum vacation days |
Breadth First Search (BFS) |
650 |
2 keys keyboard |
Breadth First Search (BFS) |
752 |
open the lock |
Breadth First Search (BFS) |
818 |
race car |
Breadth First Search (BFS) |
882 |
reachable nodes in subdivided graph |
Breadth First Search (BFS) |
1036 |
escape a large maze |
Breadth First Search (BFS) |
1145 |
binary tree coloring game |
Breadth First Search (BFS) |
1219 |
path with maximum gold |
Breadth First Search (BFS) |
1284 |
minimum number of flips to convert binary matrix to zero matrix |
Breadth First Search (BFS) |
1368 |
minimum cost to make at least one valid path in a grid |
Breadth First Search (BFS) |
1601 |
maximum number of achievable transfer requests |
Breadth First Search (BFS) |
1602 |
find nearest right node in binary tree |
Breadth First Search (BFS) |
1660 |
correct a binary tree |
Breadth First Search (BFS) |
1730 |
shortest path to get food |
Breadth First Search (BFS) |
504 |
base 7 |
Change of Base |
51 |
n queens |
Depth First Search (DFS) |
698 |
partition to k equal sum subsets |
Depth First Search (DFS) |
1020 |
number of enclaves |
Depth First Search (DFS) Breadth First Search (BFS) |
641 |
design circular deque |
Design Data Structure |
933 |
number of recent calls |
Design Data Structure |
273 |
integer to english words |
Divide and Conquer |
70 |
climbing stairs |
Dynamic Programming |
375 |
guess number higher or lower ii |
Dynamic Programming |
377 |
combination sum iv |
Dynamic Programming |
464 |
can i win |
Dynamic Programming |
486 |
predict the winner |
Dynamic Programming |
494 |
target sum |
Dynamic Programming |
629 |
k inverse pairs array |
Dynamic Programming |
639 |
decode ways ii |
Dynamic Programming |
746 |
min cost climbing stairs |
Dynamic Programming |
801 |
minimum swaps to make sequences increasing |
Dynamic Programming |
813 |
largest sum of averages |
Dynamic Programming |
983 |
minimum cost for tickets |
Dynamic Programming |
1024 |
video stitching |
Dynamic Programming |
1025 |
divisor game |
Dynamic Programming |
1027 |
longest arithmetic subsequence |
Dynamic Programming |
1216 |
valid palindrome iii |
Dynamic Programming |
1235 |
maximum profit in job scheduling |
Dynamic Programming |
1307 |
verbal arithmetic puzzle |
Dynamic Programming |
1312 |
minimum insertion steps to make a string palindrome |
Dynamic Programming |
1690 |
stone game vii |
Dynamic Programming |
1692 |
count ways to distribute candies |
Dynamic Programming |
431 |
encode n ary tree to binary tree |
Encoding and Decoding N-ary Trees Binary Trees |
865 |
smallest subtree with all the deepest nodes |
Eulerian Path |
1650 |
lowest common ancestor of a binary tree iii |
Eulerian Path |
1676 |
lowest common ancestor of a binary tree iv |
Eulerian Path |
1740 |
find distance in a binary tree |
Eulerian Path Visual Solutions |
307 |
range sum query mutable |
Fenwick Trees |
683 |
k empty slots |
Fenwick Trees |
1606 |
find servers that handled most number of requests |
Fenwick Trees |
317 |
shortest distance from all buildings |
Floyd-Warshall Breadth First Search (BFS) |
348 |
design tic tac toe |
Game Related |
529 |
minesweeper |
Game Related |
909 |
snakes and ladders |
Game Related |
950 |
reveal cards in increasing order |
Game Related |
1210 |
minimum moves to reach target with rotations |
Game Related Breadth First Search (BFS) |
538 |
convert bst to greater tree |
Greater Trees |
765 |
couples holding hands |
Greedy |
995 |
minimum number of k consecutive bit flips |
Greedy |
1090 |
largest values from labels |
Greedy |
1686 |
stone game vi |
Greedy |
132 |
palindrome partitioning ii |
Greedy Algorithm |
1349 |
maximum students taking exam |
Greedy Algorithm |
1147 |
longest chunked palindrome decomposition |
Greedy Double Ended Queues |
296 |
best meeting point |
Greedy Greedy Algorithm |
727 |
minimum window subsequence |
Greedy Greedy Algorithm |
149 |
max points on a line |
Hashing |
893 |
groups of special equivalent strings |
Hashing |
871 |
minimum number of refueling stops |
Heap |
1696 |
jump game vi |
Heap |
1655 |
distribute repeating integers |
Heap Breadth First Search (BFS) |
798 |
smallest rotation with highest score |
Interval Scheduling: |
25 |
reverse nodes in k group |
Linked-Lists |
82 |
remove duplicates from sorted list ii |
Linked-Lists |
430 |
flatten a multilevel doubly linked list |
Linked-Lists |
708 |
insert into a sorted circular linked list |
Linked-Lists |
1290 |
convert binary number in a linked list to integer |
Linked-Lists |
1634 |
add two polynomials represented as linked lists |
Linked-Lists |
448 |
find all numbers disappeared in an array |
Masks |
864 |
shortest path to get all keys |
Masks Breadth First Search (BFS) |
526 |
beautiful arrangement |
Masks Top Down DP |
474 |
ones and zeroes |
Memoization |
308 |
range sum query 2d mutable |
Memoization Fenwick Trees |
423 |
reconstruct original digits from english |
Multiset |
1742 |
maximum number of balls in a box |
Multiset |
1745 |
palindrome partitioning iv |
Multiset Prefix Sum Array |
1623 |
all valid triplets that can represent a country |
MySQL |
1633 |
percentage of users attended a contest |
MySQL |
1667 |
fix names in a table |
MySQL |
1693 |
daily leads and partners |
MySQL |
1490 |
clone n ary tree |
N-ary Trees |
1506 |
find root of n ary tree |
N-ary Trees |
1600 |
throne inheritance |
N-ary Trees |
1257 |
smallest common region |
N-ary Trees Lowest Common Ancestor |
15 |
3sum |
Other |
32 |
longest valid parentheses |
Other |
118 |
pascals triangle |
Other |
248 |
strobogrammatic number iii |
Other |
268 |
missing number |
Other |
306 |
additive number |
Other |
350 |
intersection of two arrays ii |
Other |
396 |
rotate function |
Other |
760 |
find anagram mappings |
Other |
775 |
global and local inversions |
Other |
780 |
reaching points |
Other |
800 |
similar rgb color |
Other |
821 |
shortest distance to a character |
Other |
843 |
guess the word |
Other |
858 |
mirror reflection |
Other |
884 |
uncommon words from two sentences |
Other |
887 |
super egg drop |
Other |
1001 |
grid illumination |
Other |
1015 |
smallest integer divisible by k |
Other |
1054 |
distant barcodes |
Other |
1138 |
alphabet board path |
Other |
1217 |
minimum cost to move chips to the same position |
Other |
1253 |
reconstruct a 2 row binary matrix |
Other |
1266 |
minimum time visiting all points |
Other |
1291 |
sequential digits |
Other |
1360 |
number of days between two dates |
Other |
1455 |
check if a word occurs as a prefix of any word in a sentence |
Other |
1488 |
avoid flood in the city |
Other |
1503 |
last moment before all ants fall out of a plank |
Other |
1599 |
maximum profit of operating a centennial wheel |
Other |
1610 |
maximum number of visible points |
Other |
1653 |
minimum deletions to make string balanced |
Other |
1743 |
restore the array from adjacent pairs |
Other |
1386 |
cinema seat allocation |
Other Greedy |
399 |
evaluate division |
Path Finding |
573 |
squirrel simulation |
Path Finding |
18 |
4sum |
Pointers |
713 |
subarray product less than k |
Pointers |
334 |
increasing triplet subsequence |
Prefix Sum Array |
1714 |
sum of special evenly spaced elements in array |
Prefix Sum Array |
1744 |
can you eat your favorite candy on your favorite day |
Prefix Sum Array |
688 |
knight probability in chessboard |
Probability |
808 |
soup servings |
Probability |
1377 |
frog position after t seconds |
Probability |
616 |
add bold tag in string |
Rabin-Karp |
1316 |
distinct echo substrings |
Rabin-Karp |
773 |
sliding puzzle |
Rabin-Karp Breadth First Search (BFS) |
130 |
surrounded regions |
Recursion |
131 |
palindrome partitioning |
Recursion |
139 |
word break |
Recursion |
140 |
word break ii |
Recursion |
463 |
island perimeter |
Recursion |
906 |
super palindromes |
Recursion |
1088 |
confusing number ii |
Recursion |
1301 |
number of paths with max score |
Recursion |
1548 |
the most similar path in a graph |
Recursion |
1612 |
check if two expression trees are equivalent |
Recursion Breadth First Search (BFS) |
546 |
remove boxes |
Recursion Memoization |
1240 |
tiling a rectangle with the fewest squares |
Recursion Simulation |
732 |
my calendar iii |
Scheduling: |
1157 |
online majority element in subarray |
Segment Tree |
1673 |
find the most competitive subsequence |
Segment Tree |
1335 |
minimum difficulty of a job schedule |
Segment Tree Dynamic Programming |
794 |
valid tic tac toe state |
Simulation Game Related |
749 |
contain virus |
Simulation Union-Find Visual Solutions |
1206 |
design skiplist |
Skip List |
1100 |
find k length substrings with no repeated characters |
Sliding Window |
1708 |
largest subarray length k |
Sliding Window |
646 |
maximum length of pair chain |
Sorting |
757 |
set intersection size at least two |
Sorting |
1333 |
filter restaurants by vegan friendly price and distance |
Sorting |
1356 |
sort integers by the number of 1 bits |
Sorting |
220 |
contains duplicate iii |
Sorting Double Ended Queues |
20 |
valid parentheses |
Stacks |
71 |
simplify path |
Stacks |
85 |
maximal rectangle |
Stacks |
503 |
next greater element ii |
Stacks |
604 |
design compressed string iterator |
Stacks |
1598 |
crawler log folder |
Stacks |
1106 |
parsing a boolean expression |
Stacks Parsing |
188 |
best time to buy and sell stock iv |
State Machines |
265 |
paint house ii |
State Machines |
276 |
paint fence |
State Machines |
740 |
delete and earn |
State Machines |
161 |
one edit distance |
String Manipulation |
186 |
reverse words in a string ii |
String Manipulation |
395 |
longest substring with at least k repeating characters |
String Manipulation |
557 |
reverse words in a string iii |
String Manipulation |
811 |
subdomain visit count |
String Manipulation |
824 |
goat latin |
String Manipulation |
856 |
score of parentheses |
String Manipulation |
859 |
buddy strings |
String Manipulation |
1236 |
web crawler |
String Manipulation |
454 |
4sum ii |
Sub-problem |
1242 |
web crawler multithreaded |
Threading: Breadth First Search (BFS) |
312 |
burst balloons |
Top Down DP |
329 |
longest increasing path in a matrix |
Top Down DP |
337 |
house robber iii |
Top Down DP |
471 |
encode string with shortest length |
Top Down DP |
913 |
cat and mouse |
Top Down DP |
955 |
delete columns to make sorted ii |
Top Down DP |
956 |
tallest billboard |
Top Down DP |
1043 |
partition array for maximum sum |
Top Down DP |
1125 |
smallest sufficient team |
Top Down DP |
1340 |
jump game v |
Top Down DP |
1420 |
build array where you can find the maximum exactly k comparisons |
Top Down DP |
1449 |
form largest integer with digits that add up to target |
Top Down DP |
1473 |
paint house iii |
Top Down DP |
1659 |
maximize grid happiness |
Top Down DP |
1681 |
minimum incompatibility |
Top Down DP |
1682 |
longest palindromic subsequence ii |
Top Down DP |
1691 |
maximum height by stacking cuboids |
Top Down DP |
1728 |
cat and mouse ii |
Top Down DP |
1406 |
stone game iii |
Top Down DP Game Related |
164 |
maximum gap |
Trie |
745 |
prefix and suffix search |
Trie |
820 |
short encoding of words |
Trie |
1016 |
binary string with substrings representing 1 to n |
Trie |
1178 |
number of valid words for each puzzle |
Trie |
1233 |
remove sub folders from the filesystem |
Trie |
127 |
word ladder |
Trie Breadth First Search (BFS) |
1397 |
find all good strings |
Trie Top Down DP |
839 |
similar string groups |
Trie Union-Find |
80 |
remove duplicates from sorted array ii |
Two-pointer |
1287 |
element appearing more than 25 in sorted array |
Two-pointer |
1580 |
put boxes into the warehouse ii |
Two-pointer |
128 |
longest consecutive sequence |
Union-Find |
261 |
graph valid tree |
Union-Find |
305 |
number of islands ii |
Union-Find |
547 |
friend circles |
Union-Find |
711 |
number of distinct islands ii |
Union-Find |
721 |
accounts merge |
Union-Find |
737 |
sentence similarity ii |
Union-Find |
924 |
minimize malware spread |
Union-Find |
928 |
minimize malware spread ii |
Union-Find |
990 |
satisfiability of equality equations |
Union-Find |
1061 |
lexicographically smallest equivalent string |
Union-Find |
1101 |
the earliest moment when everyone become friends |
Union-Find |
1168 |
optimize water distribution in a village |
Union-Find |
1202 |
smallest string with swaps |
Union-Find |
1258 |
synonymous sentences |
Union-Find |
1319 |
number of operations to make network connected |
Union-Find |
1579 |
remove max number of edges to keep graph fully traversable |
Union-Find |
1627 |
graph connectivity with threshold |
Union-Find |
1632 |
rank transform of a matrix |
Union-Find |
1697 |
checking existence of edge length limited paths |
Union-Find |
352 |
data stream as disjoint intervals |
Union-Find Binary Search |
1434 |
number of ways to wear different hats to each other |
Union-Find Top Down DP |
959 |
regions cut by slashes |
Union-Find Visual Solutions |
172 |
factorial trailing zeroes |
Visual Solutions |
319 |
bulb switcher |
Visual Solutions |
498 |
diagonal traverse |
Visual Solutions |
790 |
domino and tromino tiling |
Visual Solutions |
963 |
minimum area rectangle ii |
Visual Solutions |
1351 |
count negative numbers in a sorted matrix |
Visual Solutions |
1644 |
lowest common ancestor of a binary tree ii |
Visual Solutions Binary Trees Eulerian Path |
1274 |
number of ships in a rectangle |
Visual Solutions Divide and Conquer |