Educational Codeforces Round 161 (Rated for Div. 2)

Solutions for Educational Codeforces Round 161 (Rated for Div. 2) (contest 1922). 2/6 problems verified against sample I/O. Difficulty range: 800-2500.

6 items

Educational Codeforces Round 161 (Rated for Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 2/6 | Rating range: 800-2500 | Time: 13m 33s

Problem Name Rating Tags Solve Time Verified
A Tricky Template 800 constructive-algorithms, implementation, strings 4m 30s ✗
B Forming Triangles 1200 combinatorics, constructive-algorithms, math 1m 40s ✓
C Closest Cities 1300 greedy, implementation, math 1m 35s ✓
D Berserk Monsters 1900 brute-force, data-structures, dsu 1m 52s ✗
E Increasing Subsequences 1800 bitmasks, constructive-algorithms, divide-and-conquer 2m 3s ✗
F Replace on Segment 2500 dp, graph-matchings 1m 53s ✗
Practice › Codeforces Solutions › Educational Codeforces Round 161 (Rated for Div. 2) ›

CF 1922F - Replace on Segment

We are given an array of integers, each between 1 and some maximum value $x$. We want to make every element equal using a special operation: select a contiguous subsegment of the array and a value $k$ not currently present in that subsegment, then replace every element in that…
codeforces competitive-programming dp graph-matchings Jun 8, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 161 (Rated for Div. 2) ›

CF 1922A - Tricky Template

We are given three strings of equal length, and we need to construct a template string such that the first two strings match the template while the third one does not. Each position in the template can be either lowercase or uppercase.
codeforces competitive-programming constructive-algorithms implementation strings Jun 8, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 161 (Rated for Div. 2) ›

CF 1922E - Increasing Subsequences

We are asked to construct an array of integers with a very specific property: the total number of its increasing subsequences should equal a given integer $X$.
codeforces competitive-programming bitmasks constructive-algorithms divide-and-conquer greedy math Jun 8, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 161 (Rated for Div. 2) ›

CF 1922D - Berserk Monsters

We have a row of monsters, each with an attack value ai and a defense value di. Monocarp casts a berserk spell so that monsters attack their immediate neighbors each round.
codeforces competitive-programming brute-force data-structures dsu implementation math Jun 8, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 161 (Rated for Div. 2) ›

CF 1922B - Forming Triangles

We are given a set of sticks, each with a length that is a power of two. The input does not give the actual lengths directly but rather exponents $ai$ such that the stick's length is $2^{ai}$.
codeforces competitive-programming combinatorics constructive-algorithms math sortings Jun 8, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 161 (Rated for Div. 2) ›

CF 1922C - Closest Cities

We are given several cities placed along a one-dimensional number line. Each city has a coordinate, and the coordinates are strictly increasing. For each city, there exists a unique "closest" city, meaning that no two cities are equally close to it.
codeforces competitive-programming greedy implementation math Jun 8, 2026