Data Structures
array

117 problems

#

Title

Acceptance

Difficulty

1

Contains Duplicate (easy)
hash map
hash set
array
+1 more

55.5%

easy

2

Reverse Vowels (easy)
string
array
two pointers

44.3%

easy

3

string
array
two pointers
+1 more

22.6%

easy

4

array
string
two pointers
+1 more

27.9%

easy

5

array
counting
hash map

75.4%

easy

6

two pointers
array
binary search
+1 more

42.4%

easy

7

array
sorting
two pointers
+1 more

42.5%

easy

8

array
sorting
two pointers
+3 more

35.6%

easy

9

sorting
two pointers
array
+3 more

22.2%

Med.

10

sorting
array
greedy algorithm

12.2%

Med.

11

sorting
two pointers
array
+1 more

22.7%

Med.

12

array
sorting
two pointers
+1 more

29.6%

Med.

13

12.7%

Med.

14

17.3%

hard

15

sliding window
greedy algorithm
array
+1 more

46.3%

easy

16

sliding window
array
two pointers
+2 more

19.7%

easy

17

sliding window
two pointers
array
+1 more

39.5%

Med.

18

sliding window
two pointers
array
+1 more

48.8%

hard

19

23.2%

hard

20

29.0%

hard

21

24.9%

hard

22

merge intervals
array

22.0%

Med.

23

merge intervals
two pointers
array

48.0%

Med.

24

sorting
greedy algorithm
array

28.1%

Med.

25

48.4%

hard

26

sorting
cyclic sort
array

48.3%

easy

27

42.5%

easy

28

array
cyclic sort
sorting
+1 more

54.3%

easy

29

49.2%

easy

30

array
cyclic sort
two pointers
+1 more

67.2%

easy

31

48.1%

easy

32

28.9%

Med.

33

16.8%

hard

34

linked list
recursion
sorting
+4 more

80.1%

easy

35

linked list
array
recursion
+1 more

53.1%

Med.

36

linked list
linked list reversal
recursion
+1 more

51.7%

Med.

37

30.1%

easy

38

46.7%

Med.

39

31.5%

easy

40

stack
monotonic stack
array
+1 more

55.4%

easy

41

monotonic stack
array
stack

54.9%

easy

42

37.1%

Med.

43

subsets
array
stack
+3 more

67.6%

Med.

44

greedy algorithm
stack
string
+1 more

12.7%

hard

45

hash map
counting
array
+1 more

61.4%

easy

46

hash map
counting
array
+1 more

0.0%

easy

47

hash map
counting
string
+1 more

0.0%

easy

48

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

64.1%

Med.

49

graph
depth-first search
breadth-first search
+2 more

42.8%

easy

50

graph algorithms
depth-first search
recursion
+2 more

0.0%

easy

51

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

49.4%

easy

52

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

62.6%

Med.

53

binary search
sorting
graph algorithms
+3 more

62.6%

hard

54

subsets
backtracking
array
+1 more

60.4%

easy

55

subsets
array
backtracking

40.4%

easy

56

recursion
backtracking
array
+2 more

58.9%

Med.

57

string
backtracking
recursion
+1 more

70.2%

hard

58

binary tree
binary search tree
recursion
+2 more

30.1%

hard

59

binary search
sorting
array
+1 more

32.8%

easy

60

binary search
array
sorting

23.7%

Med.

61

binary search
array
recursion

36.9%

Med.

62

binary search
array
sorting

39.4%

Med.

63

binary search
array
recursion
+1 more

33.7%

Med.

64

binary search
array
sorting

24.1%

Med.

65

binary search
array
sorting
+1 more

35.0%

easy

66

binary search
array
recursion
+1 more

31.1%

Med.

67

23.1%

Med.

68

binary search
array
recursion
+1 more

24.3%

Med.

69

array
hash map
hash set
+3 more

82.6%

easy

70

array
sorting
counting
+1 more

68.2%

Med.

71

58.3%

hard

72

heap
top k elements
priority queue
+2 more

63.6%

easy

73

top k elements
sorting
array
+2 more

42.7%

easy

74

heap
priority queue
top k elements
+3 more

25.0%

easy

75

top k elements
sorting
array
+2 more

55.9%

Med.

76

heap
priority queue
top k elements
+2 more

52.7%

Med.

77

binary search
sorting
array
+2 more

26.7%

Med.

78

greedy algorithm
hash map
array

22.7%

Med.

79

sorting
array
top k elements

51.3%

Med.

80

greedy algorithm
string
backtracking
+3 more

44.5%

hard

81

31.4%

hard

82

string
recursion
backtracking
+3 more

33.1%

easy

83

greedy algorithm
array
sorting
+1 more

30.4%

Med.

84

greedy algorithm
backtracking
string matching
+3 more

15.3%

Med.

85

21.8%

Med.

86

dynamic programming
recursion
backtracking
+2 more

44.6%

hard

87

depth-first search
backtracking
graph algorithms
+3 more

28.7%

Med.

88

recursion
backtracking
divide and conquer
+1 more

36.3%

Med.

89

string
string matching
trie
+3 more

30.5%

easy

90

string
array
dynamic programming
+3 more

53.0%

Med.

91

36.8%

Med.

92

hash map
sorting
array
+1 more

83.4%

easy

93

array
backtracking
stack
+1 more

36.5%

Med.

94

greedy algorithm
sorting
array

20.2%

Med.

95

sliding window
two pointers
array
+1 more

33.6%

Med.

96

prefix sum
array
two pointers
+1 more

42.7%

easy

97

array
prefix sum
recursion
+1 more

67.0%

easy

98

prefix sum
hash map
array
+1 more

29.0%

Med.

99

prefix sum
sliding window
array
+1 more

56.6%

Med.

100

prefix sum
hash map
array
+1 more

50.5%

Med.