Patterns
counting

24 problems

​

#

Title

Acceptance

Difficulty

1

Pangram (easy)
string
hash map
hashing
+1 more

31.1%

easy

2

Number of Good Pairs (easy)
array
counting
hash map

75.4%

easy

3

array
sorting
two pointers
+1 more

29.6%

Med.

4

48.1%

easy

5

55.3%

easy

6

0.0%

easy

7

hash map
counting
array
+1 more

61.4%

easy

8

hash map
counting
array
+3 more

0.0%

easy

9

39.7%

easy

10

0.0%

easy

11

greedy algorithm
counting
string

24.1%

easy

12

0.0%

easy

13

string
hash map
counting
+1 more

56.7%

easy

14

hash map
counting
string
+1 more

0.0%

easy

15

array
hash map
hash set
+3 more

82.6%

easy

16

array
sorting
counting
+1 more

68.2%

Med.

17

top k elements
sorting
array
+2 more

55.9%

Med.

18

sorting
counting
hash map
+2 more

80.5%

Med.

19

dynamic programming
recursion
backtracking
+2 more

44.6%

hard

20

prefix sum
sliding window
array
+1 more

56.6%

Med.

21

prefix sum
hash map
array
+1 more

50.5%

Med.

22

prefix sum
array
hash map
+1 more

45.2%

Med.

23

array
two pointers
greedy algorithm
+1 more

51.3%

easy

24

32.0%

Med.