====== Codeforces ======

===== 난이도 체계 비교 =====
  * 솔브드 레이팅이 매겨진 문제들만 샘플링

  * Hello 2020 (https://codeforces.com/contest/1284)

| New Year and Naming | {{myicon>b2}} | *800 |
| New Year and Ascent Sequence | {{myicon>g3}} | *1400 |
| New Year and Permutation | {{myicon>g2}} | *1600 |
| New Year and Conference | {{myicon>p2}} | *2100 | 
| New Year and Castle Construction | {{myicon>d4}} | *2500 |
| New Year and Social Network | {{myicon>r4}} | *3200 |
| Seollal | {{myicon>r4}} | *3300 | 


  * Codeforces Round 620 (Div. 2) (https://codeforces.com/contest/1304)

| Two Rabbits | {{myicon>b2}} | *800 |
| Longest Palindrome | {{myicon>s1}} | *1100 |
| Air Conditioner | {{myicon>g4}} | *1500 |
| Shortest and Longest LIS | {{myicon>p5}} | *1800 |
| 1-Trees and Queries | {{myicon>p4}} | *2000 |
| Animal Observation (easy version) | {{myicon>p3}} | *2300 |
| Animal Observation (hard version) | {{myicon>p1}} | *2400 |

  * Codeforces Round 688 (Div. 2) (https://codeforces.com/contest/1453)

| Cancel the Trains | {{myicon>b3}} | *800 |
| Suffix Operations | {{myicon>g3}} | *1400 |
| Triangles | {{myicon>g2}} | *1700 |
| Checkpoints | {{myicon>g1}} | *1900 |
| Dog Snacks | {{myicon>p3}} | *2300 |
| Even Harder | {{myicon>d5}} | *2700 |