Core Pillars

Patterns

238

Algorithms

173

Data Structures

239

two pointers

50

fast and slow pointers

8

sliding window

15

merge intervals

9

cyclic sort

8

linked list reversal

7

stack

21

monotonic stack

9

hash map

44

level order traversal

13

tree breadth first search

19

tree depth first search

15

graph

23

matrix traversal

11

two heaps

3

subsets

14

modified binary search

14

bitwise xor

4

top k elements

15

k-way merge

4

greedy algorithm

25

0/1 knapsack

5

backtracking

22

trie

6

topological sort

9

union-find

5

prefix sum

10

counting

47

monotonic queue

1

simulation

29

linear sorting

1

serialize and deserialize

3

clone

1

#

Title

Acceptance

Difficulty

1

Contains Duplicate (easy)
hash map
hash set
array
+2 more

55.5%

easy

2

string
hash set
counting
+1 more

31.0%

easy

3

Reverse Vowels (easy)
two pointers
string
array

44.2%

easy

4

string
two pointers
simulation

22.5%

easy

5

string
hash map
counting
+1 more

38.3%

easy

6

array
string
two pointers
+2 more

27.8%

easy

7

array
counting
hash map
+1 more

75.4%

easy

8

binary search
recursion

15.3%

Med.

9

two pointers
array
binary search
+1 more

42.3%

easy

10

42.4%

easy

11

two pointers
array
sorting

35.5%

easy

12

two pointers
sorting
array
+1 more

22.2%

Med.

13

two pointers
array
sorting

12.2%

Med.

14

array
two pointers
sorting
+1 more

22.6%

Med.

15

two pointers
sorting
array
+1 more

29.5%

Med.

16

17.2%

Med.

17

16.7%

Med.

18

12.7%

Med.

19

linked list
fast and slow pointers
two pointers

64.5%

easy

20

linked list
fast and slow pointers
two pointers

59.8%

easy

21

linked list
fast and slow pointers
two pointers

49.7%

Med.

22

fast and slow pointers
simulation
hash set
+1 more

47.2%

Med.

23

linked list
two pointers
fast and slow pointers
+1 more

28.9%

Med.

24

linked list
fast and slow pointers
linked list reversal
+1 more

56.3%

Med.

25

fast and slow pointers
array
simulation
+1 more

17.2%

hard

26

sliding window
array
prefix sum
+1 more

46.2%

easy

27

sliding window
array
two pointers

19.6%

easy

28

28.0%

Med.

29

sliding window
hash map
array
+1 more

39.4%

Med.

30

29.8%

hard

31

sliding window
array
two pointers
+1 more

48.7%

hard

32

sliding window
hash map
string
+2 more

16.2%

hard

33

string
sliding window
hash map
+1 more

29.0%

hard

34

20.0%

hard

35

sliding window
hash map
string
+1 more

23.1%

hard

36

29.0%

hard

37

24.6%

hard

38

merge intervals
sorting
array
+1 more

31.2%

Med.

39

merge intervals
array
greedy algorithm

21.9%

Med.

40

merge intervals
two pointers
array

47.9%

Med.

41

merge intervals
sorting
array

28.0%

Med.

42

merge intervals
heap
greedy algorithm
+3 more

25.8%

hard

43

merge intervals
heap
priority queue
+2 more

43.0%

hard

44

merge intervals
heap
sorting
+2 more

48.4%

hard

45

cyclic sort
sorting
array
+1 more

48.2%

easy

46

cyclic sort
bitwise xor
array
+2 more

42.4%

easy

47

cyclic sort
array
sorting

54.2%

easy

48

cyclic sort
array
sorting

49.1%

easy

49

cyclic sort
array
sorting

67.1%

easy

50

48.0%

easy

51

28.8%

Med.

52

16.7%

hard

53

linked list
linked list reversal
two pointers
+1 more

80.1%

easy

54

linked list
linked list reversal
two pointers

31.4%

Med.

55

linked list reversal
linked list
two pointers

53.0%

Med.

56

51.9%

Med.

57

linked list
two pointers
simulation

22.8%

Med.

58

stack
string
depth-first search
+1 more

30.1%

easy

59

85.1%

easy

60

46.7%

Med.

61

array
stack
two pointers
+3 more

31.5%

easy

62

69.7%

easy

63

25.2%

Med.

64

linked list
linked list reversal
monotonic stack
+1 more

41.9%

easy

65

58.5%

easy

66

monotonic stack
hash map
array
+1 more

55.3%

easy

67

monotonic stack
array
stack

54.8%

easy

68

37.0%

Med.

69

monotonic stack
array
stack
+1 more

67.6%

Med.

70

greedy algorithm
monotonic stack
string
+1 more

12.6%

hard

71

55.3%

easy

72

0.0%

easy

73

hash map
counting
array
+1 more

61.4%

easy

74

hash map
counting
array
+1 more

0.0%

easy

75

39.7%

easy

76

0.0%

easy

77

string
array
hash map
+1 more

24.1%

easy

78

string
hash map
array
+1 more

0.0%

easy

79

string
hash map
counting
+1 more

56.7%

easy

80

hash map
string
counting

0.0%

easy

81

binary tree
tree breadth first search
level order traversal
+2 more

89.3%

easy

82

tree breadth first search
binary tree
breadth-first search
+2 more

90.5%

Med.

83

binary tree
tree breadth first search
level order traversal
+3 more

32.1%

Med.

84

binary tree
tree breadth first search
level order traversal
+3 more

54.0%

Med.

85

tree breadth first search
binary tree
queue
+2 more

64.0%

Med.

86

binary tree
tree breadth first search
level order traversal
+2 more

56.9%

Med.

87

n-ary tree
level order traversal
tree breadth first search
+3 more

92.5%

hard

88

tree breadth first search
binary tree
level order traversal
+3 more

73.4%

easy

89

binary tree
tree breadth first search
level order traversal
+2 more

89.3%

easy

90

tree breadth first search
binary tree
queue
+2 more

64.0%

Med.

91

tree breadth first search
level order traversal
binary tree
+1 more

82.0%

easy

92

binary tree
tree depth first search
tree breadth first search
+3 more

21.3%

easy

93

binary tree
tree breadth first search
queue
+1 more

63.9%

easy

94

tree breadth first search
level order traversal
binary tree
+2 more

78.1%

Med.

95

binary tree
tree breadth first search
level order traversal
+1 more

80.1%

Med.

96

binary tree
tree breadth first search
level order traversal
+1 more

76.2%

easy

97

binary tree
recursion
depth-first search
+1 more

38.2%

easy

98

binary tree
tree depth first search
recursion
+1 more

56.9%

Med.

99

binary tree
tree depth first search
recursion
+1 more

68.9%

Med.

100

tree depth first search
binary tree
recursion

25.9%

Med.

Topics

array

113

recursion

73

string

58

sorting

55

two pointers

50

counting

47

hash map

44

depth-first search

38

breadth-first search

36

binary tree

32

simulation

29

priority queue

27

heap

26

greedy algorithm

25
+42 more