Competitive Programming

Codeforces

Awesome list for CP: https://codeforces.com/blog/entry/23054 Lesson: Stop overestimating yourself.

How is the elo of a problem calculated?

Problem rating of x is supposed to mean that about 50% of coders rated x can solve that problem, about 75% coders rated x+200 can solve, or about 90% rated x+400 can solve the problem. > https://codeforces.com/blog/entry/62865

So if I want to reach 2000, I should be able to solve 2000 problems ~50% of the time.

Goal: Keep upsolving C and D. It’s going to be very difficult, but you really need to continue practicing and upsolving these problems. There is no point in just doing A and B problems, unless you really are using them to practice speed.

I need to do those contest simulations, but rather than doing the virtual simulation, just time yourself. Alternatively, binary search but that’s too easy. Problems I need to do:

• https://codeforces.com/contest/1567/problem/C (1600 problem)
• https://codeforces.com/contest/1405/problem/C (1500 problem)
• https://codeforces.com/contest/305/problem/B (continued fractions)
• https://codeforces.com/contest/356/problem/A (union find)
• https://codeforces.com/problemset/problem/1705/D
• Started implementing, but my brain isn’t working: https://codeforces.com/problemset/problem/1553/D
• https://codeforces.com/contest/271/problem/D (string hashing)
• https://codeforces.com/contest/1527/problem/C
• https://codeforces.com/problemset/problem/1620/E (harder union find)
• https://codeforces.com/contest/1543/problem/C
• https://codeforces.com/contest/1543/problem/D2
• https://codeforces.com/contest/1537/problem/E2 (need string hashing)
• https://codeforces.com/problemset/problem/1621/B

Problems I have thought about but don’t know:

• https://codeforces.com/contest/1604/problem/D (modular arithmetic, 1500)
• https://codeforces.com/problemset/problem/1554/B

Hard Problems I read editorial but still don’t know:

• https://codeforces.com/problemset/problem/1616/C (1500)

To try again later:

• https://codeforces.com/problemset/problem/1553/D

Solved but it’s iffy…, like I don’t understand:

• https://codeforces.com/problemset/problem/1542/C
• https://codeforces.com/problemset/problem/1554/C https://c2-ladders.com/

Such an amazing platform. Some Blogs https://codeforces.com/blog/entry/48417

Highest Tags Per Problem

https://codeforces.com/blog/entry/74822 Focus on DP if you want to solve D and E!!

• A — implementation: 426, math: 176, brute force: 145
• B — implementation: 321, greedy: 180, math: 171
• C — greedy: 141, implementation: 137, math: 107
• D — dp: 130, greedy: 103, math: 99
• E — dp: 147, data structures: 122, math: 80
• F — dp: 85, data structures: 55, graphs: 38
• G — data structures: 28, dp: 20, math: 18
• H — data structures: 4, trees: 4, constructive algorithms: 3