Leet Code Triggers

Question 1

arrays / hashing

Answer 1

find pair
seen before
duplicates
frequency
count occurrences
first unique
group by

Question 2

two pointers

Answer 2

sorted array
pair sum
palindrome
remove duplicates
partition
compare both ends

Question 2

sliding window

Answer 2

substring
subarray
contiguous
longest
shortest
max/min window
at most k
exactly k

Question 3

stack

Answer 3

next greater
next smaller
previous greater
histogram
temperature
stock span

Question 4

heap / priority queues

Answer 4

top k
kth largest
kth smallest
stream
contiguously updating max/min
scheduling
merge sorted lists

Question 5

binary search

Answer 5

sorted
rotated sorted
search target
minimum feasible value
maximize minimum
minimize maximum
find first true

Question 6

linked list

Answer 6

reverse
remove nth
cycle
merge lists
reorder
in place
constant extra space

Question 7

trees

Answer 7

path
depth
level
traversal
ancestor

Question 8

graphs

Answer 8

dependencies
connectivity
shortest path
islands
scheduling
network

Question 9

intervals

Answer 9

meetings
overlapping times
ranges
scheduling

Question 10

backtracking

Answer 10

all subsets
combinations
choose k elements
reorder
all possible arrangements
every ordering
maze
path exists
word search
route generation

Question 11

dynamic programming

Answer 11

count ways
max/min path
choose or skip
subsequence
optimization