Solved by shepherd_nullptr

#	Title	# Solved	Avg. Tries
1657	두부장수 장홍준	709	2.02
2150	Strongly Connected Component	4,767	2.21
3491	Skyscraper Floors	10	10.80
3653	Movie collection	2,899	2.21
3679	Simple Polygon	1,030	3.91
4315	Marbles on a tree	112	2.26
5012	Mega Inversions	453	2.13
5820	경주	598	4.72
5822	악어의 지하 도시	115	2.43
6549	Largest Rectangle in a Histogram	10,982	3.64
9126	Cycling	15	5.40
9250	문자열 집합 판별	1,165	2.76
9537	Magical GCD	158	3.49
10745	Censoring	73	5.21
11280	2-SAT - 3	1,995	1.95
11438	LCA 2	7,208	3.03
11689	GCD(n, k) = 1	4,509	2.51
13007	ntopia	53	1.34
13426	단순 경로의 수열의 도치	9	1.78
14258	XOR 그룹	70	2.56
14749	Grasshopper Route	83	2.57
16044	Prefix Free Code	16	1.75
16229	반복 패턴	217	4.49
17004	Subsequences in Substrings	34	1.15
17157	Hobson’s Trains	32	2.53
18118	7-세그먼트 디스플레이	109	4.26
21148	TripTik	10	3.10
21225	Index	59	1.49
21586	Another Substring Query Problem	37	3.97
21592	Longest Common Substring	73	1.99
21882	Coins on a tree	48	3.65
22911	Hidden Pancakes	47	1.79
23078	Star Trappers	13	3.92
23195	Gene Folding	26	1.73
23196	Landscape Generator	46	1.41
24023	아기 홍윤	340	2.26
24452	交易計画 (Trade Plan)	30	1.93
24602	Tree Hopping	47	2.47
25913	전투 시뮬레이션	42	3.31
26130	Crystal Crosswind	28	1.25
26140	Take On Meme	18	1.17
26141	Where Am I?	22	1.50
27576	Eroding Pillars	7	3.00
27592	Triangle Containment	18	1.44
27889	Exceptional School Name	4,220	1.41
28088	응애(EASY)	175	1.96
28145	A Tree and Two Edges	19	2.21
29772	병사 분배	19	2.42
30880	Query Isn’t ROCK	42	4.40
30947	Cakes	18	1.39

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