Data Structures
hash set

10 problems

#

Title

Acceptance

Difficulty

1

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

55.4%

easy

2

string
hash set
counting
+1 more

30.9%

easy

3

17.2%

Med.

4

Happy Number (medium)
fast and slow pointers
simulation
hash set
+1 more

47.1%

Med.

5

matrix
depth-first search
hash set
+3 more

62.5%

Med.

6

44.2%

Med.

7

string
dynamic programming
hash set
+2 more

53.0%

Med.

8

matrix
hash set
matrix traversal
+3 more

35.7%

Med.

9

dynamic programming
string
recursion
+3 more

40.7%

Med.

10

31.9%

Med.