Data Structures
array

109 problems

#

Title

Acceptance

Difficulty

1

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

55.5%

easy

2

string
array
hash map
+1 more

31.0%

easy

3

Reverse Vowels (easy)
string
two pointers
array
+2 more

44.2%

easy

4

array
string
two pointers
+3 more

27.8%

easy

5

array
counting
hash map

75.4%

easy

6

two pointers
array
binary search
+1 more

42.4%

easy

7

array
two pointers
sorting
+3 more

42.5%

easy

8

array
sorting
two pointers
+3 more

35.5%

easy

9

array
sorting
two pointers

22.2%

Med.

10

sorting
array
greedy algorithm

12.2%

Med.

11

sorting
two pointers
array
+1 more

22.6%

Med.

12

two pointers
sorting
array
+1 more

29.5%

Med.

13

12.7%

Med.

14

array
graph algorithms
recursion
+1 more

17.2%

hard

15

sliding window
greedy algorithm
array
+1 more

46.3%

easy

16

sliding window
array
two pointers

19.7%

easy

17

sliding window
array
two pointers
+1 more

39.4%

Med.

18

48.7%

hard

19

29.0%

hard

20

24.7%

hard

21

merge intervals
sorting
array
+1 more

31.2%

Med.

22

merge intervals
array
greedy algorithm

21.9%

Med.

23

merge intervals
two pointers
array

48.0%

Med.

24

greedy algorithm
sorting
array
+1 more

25.8%

hard

25

48.4%

hard

26

sorting
cyclic sort
array
+1 more

48.3%

easy

27

42.4%

easy

28

array
counting
sorting
+1 more

54.3%

easy

29

array
sorting
two pointers
+2 more

49.1%

easy

30

67.1%

easy

31

48.0%

easy

32

28.8%

Med.

33

16.7%

hard

34

linked list
recursion
sorting
+4 more

80.1%

easy

35

46.7%

Med.

36

array
stack
two pointers
+3 more

31.5%

easy

37

58.6%

easy

38

stack
monotonic stack
array
+1 more

55.3%

easy

39

monotonic stack
array
stack

54.8%

easy

40

monotonic stack
array
stack
+1 more

67.6%

Med.

41

greedy algorithm
stack
string
+1 more

12.6%

hard

42

hash map
counting
array
+1 more

61.4%

easy

43

hash map
counting
array
+1 more

0.0%

easy

44

string
array
hash map
+1 more

24.1%

easy

45

string
hash map
array
+1 more

0.0%

easy

46

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

90.5%

Med.

47

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

64.0%

Med.

48

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

64.0%

Med.

49

binary tree
depth-first search
recursion
+2 more

24.5%

Med.

50

matrix
breadth-first search
depth-first search
+4 more

47.4%

easy

51

breadth-first search
depth-first search
recursion
+3 more

38.4%

easy

52

array
matrix
depth-first search
+2 more

27.3%

easy

53

sliding window
priority queue
array
+1 more

32.2%

hard

54

greedy algorithm
priority queue
linked list
+2 more

32.2%

hard

55

subsets
backtracking
array
+1 more

60.3%

easy

56

recursion
backtracking
array
+2 more

58.8%

Med.

57

binary search
sorting
array
+1 more

32.7%

easy

58

binary search
array
sorting
+1 more

23.7%

Med.

59

binary search
array
string
+1 more

36.8%

Med.

60

binary search
array
sorting

39.3%

Med.

61

33.7%

Med.

62

binary search
sorting
array
+2 more

24.0%

Med.

63

binary search
array
greedy algorithm

35.0%

easy

64

31.1%

Med.

65

23.0%

Med.

66

binary search
sorting
array
+1 more

24.2%

Med.

67

array
hash map
hash set
+3 more

82.6%

easy

68

array
sorting
counting
+1 more

68.1%

Med.

69

58.2%

hard

70

top k elements
priority queue
array
+1 more

63.5%

easy

71

top k elements
sorting
array
+2 more

42.7%

easy

72

priority queue
heap
k-way merge
+3 more

25.0%

easy

73

heap
priority queue
top k elements
+2 more

52.7%

Med.

74

binary search
sorting
array
+1 more

26.6%

Med.

75

counting
greedy algorithm
array
+1 more

22.7%

Med.

76

sorting
priority queue
array
+1 more

51.2%

Med.

77

priority queue
k-way merge
array
+2 more

31.4%

hard

78

greedy algorithm
array
sorting
+1 more

30.4%

Med.

79

21.8%

Med.

80

subsets
dynamic programming
recursion
+2 more

55.6%

hard

81

backtracking
recursion
array
+2 more

46.3%

Med.

82

recursion
backtracking
divide and conquer
+1 more

36.3%

Med.

83

string
string matching
trie
+3 more

30.5%

easy

84

string
trie
sorting
+3 more

36.8%

Med.

85

hash map
sorting
array
+1 more

83.4%

easy

86

array
backtracking
stack

36.4%

Med.

87

greedy algorithm
sorting
array

20.2%

Med.

88

sliding window
two pointers
array
+1 more

33.6%

Med.

89

prefix sum
array
two pointers
+1 more

42.7%

easy

90

array
prefix sum
recursion
+1 more

67.0%

easy

91

prefix sum
hash map
array
+1 more

29.0%

Med.

92

50.5%

Med.

93

73.9%

Med.

94

prefix sum
array
hash map
+1 more

45.2%

Med.

95

hash map
two pointers
array
+1 more

65.9%

easy

96

array
two pointers
greedy algorithm
+1 more

51.2%

easy

97

stack
monotonic stack
array
+2 more

49.6%

Med.

98

string
hash map
sorting
+1 more

75.6%

Med.

99

matrix
hash set
hash map
+2 more

35.8%

Med.

100

array
prefix sum
two pointers

64.3%

Med.