立命合宿2017C

1. 2017/03/242017 Day3
2017 Day3
C:
:
:
:
:

2. 2017/03/242017 Day3
•
• N
•
• 2
• : 1≤N≤10,000 20,000

3. 2017/03/242017 Day3
• : 3 2 5 1 4
• 1: ? 2 3
→ 1: 1
• 2: ? 5 4
→ 2: 2
• ...
1
2

4. 2017/03/242017 Day3
(1)
1. 1 (1 )
2. 1 2~N
1
? 1 2 → 2
: 3 2 5 1 4
? 1 3 → 3 ? 1 4 → 1 ? 1 5 → 1
1
4?
5?
4?
5?
2?2?3? 3?

5. 2017/03/242017 Day3
(2)
3. 1 x
→ x
4. x x
→
5.
? 1 2 → 2
: 3 2 5 1 4
? 1 3 → 3 ? 1 4 → 1 ? 1 5 → 1
? 3 1 → 3 ? 3 2 → 1 ? 3 4 → 4 ? 3 5 → 2
3 2 5 1 4

6. 2017/03/242017 Day3
( ) ( )
•
• (∈ )
DFS2
1
2

7. 2017/03/242017 Day3
Writer
• : 38 lines, 702 bytes (C++)
• : 30 lines, 793 bytes (C++)
• : 25 lines, 573 bytes (C++)
27 lines, 804 bytes (Java)
18 lines, 329 bytes (Python)

8. 2017 Day3 2017/03/24
• Accept / Submission
• 36.67% (22/60)
• First Acceptance
• On-line: iak (00:11)
• On-site: iak (00:11)