Errors and Notices

Notice!

binary, hex, ...: how to handle negative case
hash table, list, min, max problems: duplicates! 414
Anytime, look up nearest sth. think of binary-search!!! 475, random sample
Stack in python: implemented by list

double pointer / double direction:

238

numerical:

456

priority queue:

378 (generally with a heap)

bit operation:

371

bfs, dfs:

332: Euler graph

dp:

260
264
309: insight of two dp record keeping

algorithm:

240: search order
287
400
442
456: 132 pattern

tree:

230: in-order traversal must record visited! otherwise, a while loop to push all left inside while; then, only push right in the outer loop
310: think carefully about the optimim solution
437

hash_table:

220, 274: idea of bucket-sort
447

string:

179, 459

stack:

496, 173

trie:

208

logic:

223

system:

535
284: iterator

sampling:

380: random set with O(1) insert, delete and get_random
398 reservoir sampling

geometry:

391: perfect square (think from corner points)
587: convex hull algorithm