Educational Codeforces Round 168 (Rated for Div. 2)

Solutions for Educational Codeforces Round 168 (Rated for Div. 2) (contest 1997). 3/6 problems verified against sample I/O. Difficulty range: 800-2700.

6 items

Educational Codeforces Round 168 (Rated for Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 3/6 | Rating range: 800-2700 | Time: 16m 22s

Problem Name Rating Tags Solve Time Verified
A Strong Password 800 brute-force, implementation, strings 2m 40s ✗
B Make Three Regions 1100 constructive-algorithms, two-pointers 2m 48s ✓
C Even Positions 1100 constructive-algorithms, data-structures, greedy 2m 20s ✓
D Maximize the Root 1500 binary-search, dfs-and-similar, dp 2m 36s ✓
E Level Up 2200 binary-search, brute-force, data-structures 2m 40s ✗
F Chips on a Line 2700 brute-force, combinatorics, dp 3m 18s ✗
Practice › Codeforces Solutions › Educational Codeforces Round 168 (Rated for Div. 2) ›

CF 1997F - Chips on a Line

We are given a one-dimensional line with positions numbered from 1 to $x$. We must place exactly $n$ chips on these positions, allowing multiple chips at the same position.
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CF 1997E - Level Up

In this problem, Monocarp is traversing a linear sequence of monsters, each with a level. He starts at level 1 and can fight monsters whose levels are at least as high as his current level. Whenever he fights k monsters, he levels up by one.
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CF 1997D - Maximize the Root

We are given a rooted tree. Every vertex contains a non-negative number. An operation can be applied to any non-leaf vertex. When we choose a vertex $v$, we increase the value at $v$ by one and simultaneously decrease every other vertex in the subtree of $v$ by one.
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CF 1997B - Make Three Regions

We have a grid with only two rows. Some cells are free (.), some are blocked (x). Free cells form a graph where adjacent cells sharing a side are connected. A connected region is simply a connected component of this graph.
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CF 1997A - Strong Password

We are asked to strengthen a password by inserting exactly one lowercase letter anywhere in an existing string. The password's strength is quantified by the time it takes to type it. Typing rules are simple: the first character always takes two seconds.
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CF 1997C - Even Positions

We are given a bracket sequence of even length, but every character at an odd position has been erased. Only the brackets at positions 2, 4, 6, ... remain.
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