CodeCraft-21 and Codeforces Round #711 (Div. 2) Editorial

Правка en16, от ninja_28, 2021-04-11 21:29:29

# 1498A - GCD Sum

#### Video Editorial

Author and Problemsetting: ninja_28
Editorialist: sigma_g

Hint
Hint 2
Hint 3
Solution
Corner cases
C++ solution
Python solution

# 1498B - Box Fitting

#### Video Editorial

Author and Editorialist: sigma_g
Problemsetting: ninja_28

Hint
Hint 2
Solution summary
Solution implementation
Another implementation
Proof of correctness - brief
Proof of correctness - elaborate
Alternate implementation with easier proof
Does this solution work when block widths are not a power of two?
C++ solution
Python solution
C++ solution - multiset
C++ solution for easier proof

# 1498C - Planar Reflections

#### Video Editorial

Author, Problemsetter and Editorialist: sigma_g

Hint 1
Solution idea
Solution details
Implementation details
Note
C++ solution
Python Iterative solution

# 1498D - Bananas in a Microwave

#### Video Editorial

Author: shash42
Problemsetting and Editorialist: sigma_g

Brute force solution
Optimizing the brute force: hint
Optimizing the brute force: hint 2
Optimizing the brute force: details
Optimized solution implementation
Common mistakes
C++ solution
Python solution

# 1498E - Two Houses

Author, Problemsetting and Editorialist: dixitgarg

Description
Hint1
Proof of unique topological sorting
Hint2
Proof
Hint3
C++ solution
Python solution

# 1498F - Christmas Game

Author: nikhil_c
Problemsetting and editorialist: sigma_g

How do we solve a standard Nim game on arrays?
How to solve tree nim game for one rooting if K = 1: classifying odd/even steps
How to solve tree nim game for one rooting if K = 1: how bad are even steps
Reducing tree nim game to linear array: the stair case nim
Extending to general K
Calculating the answer for all roots
C++ solution
Python solution

#### История

Правки

Rev. Язык Кто Когда Δ Комментарий
en16 ninja_28 2021-04-11 21:29:29 1688 Reverted to en14
en15 ninja_28 2021-03-31 08:03:57 1688
en14 ninja_28 2021-03-30 19:10:58 1 Tiny change: 'n (x + y -1) / y;\n}' -> 'n (x + y - 1) / y;\n}'
en13 ninja_28 2021-03-30 19:10:08 1 Tiny change: 'n (x + y - 1) / y;\n}' -> 'n (x + y -1) / y;\n}' (published)
en12 ninja_28 2021-03-30 19:09:14 0 Tiny change: 'rn (x + y - 1) / y;\' -> 'rn (x + y \- 1) / y;\' (saved to drafts)
en11 ninja_28 2021-03-30 19:07:09 0 Tiny change: ' LL y) {\n return (x ' -> ' LL y) {\nreturn (x '
en10 ninja_28 2021-03-30 19:04:13 0 Tiny change: 'urn (x + y - 1) / y;\n}' -> 'urn (x + y1) / y;\n}'
en9 ninja_28 2021-03-30 08:46:56 638
en8 ninja_28 2021-03-29 20:59:49 40
en7 ninja_28 2021-03-29 20:46:59 33
en6 ninja_28 2021-03-29 20:43:20 1797
en5 ninja_28 2021-03-29 20:32:45 3087
en4 ninja_28 2021-03-29 20:12:27 152 Tiny change: 'A: GCD Sum\n========' -> 'A: GCD Sum [problem:1498A]\n========'
en3 ninja_28 2021-03-29 20:09:19 8594
en2 ninja_28 2021-03-29 19:57:29 8154 Tiny change: 'rn (x + y &mdash; 1) / y;\n' -> 'rn (x + y - 1) / y;\n' (published)
en1 ninja_28 2021-03-29 19:49:16 32671 Initial revision (saved to drafts)