Codeforces Round 964 (Div. 4)

Solutions for Codeforces Round 964 (Div. 4) (contest 1999). 4/8 problems verified against sample I/O. Difficulty range: 800-1700.

8 items

Codeforces Round 964 (Div. 4)

Type: Div. 4 | Problems: 8 | Verified: 4/8 | Rating range: 800-1700 | Time: 17m 35s

Problem Name Rating Tags Solve Time Verified
A A+B Again? 800 implementation, math 1m 17s ✗
B Card Game 1000 brute-force, constructive-algorithms, implementation 1m 49s ✓
C Showering 800 greedy, implementation 2m 19s ✓
D Slavic's Exam 1100 greedy, implementation, strings 2m 44s ✗
E Triple Operations 1300 dp, implementation, math 3m 7s ✓
F Expected Median 1500 combinatorics, math 2m 8s ✓
G1 Ruler (easy version) 1500 binary-search, interactive 1m 37s ✗
G2 Ruler (hard version) 1700 binary-search, interactive, ternary-search 2m 34s ✗
Practice › Codeforces Solutions › Codeforces Round 964 (Div. 4) ›

CF 1999G2 - Ruler (hard version)

We are asked to find a missing number on a special ruler, which behaves almost like a normal ruler but skips a single value $x$ between 2 and 999. If you try to measure an object smaller than $x$, the ruler gives the correct length.
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CF 1999G1 - Ruler (easy version)

We are interacting with a hidden parameter $x$ between 2 and 999 that defines a faulty measuring device. Whenever we measure a length $y$, the device behaves normally for small values, but once the true length reaches $x$ or more, it consistently over-reports by exactly 1 unit.
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CF 1999E - Triple Operations

We are given a consecutive sequence of integers from $l$ to $r$ inclusive, written on a board. Ivy can repeatedly perform an operation on any two numbers $x$ and $y$: she replaces them with $3x$ and $lfloor y/3 rfloor$.
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CF 1999F - Expected Median

We are given a binary array containing only 0 and 1. For every subsequence of length k, where k is odd, we compute its median and add all these medians together. The array is binary, which changes the nature of the median completely.
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CF 1999D - Slavic's Exam

The task asks for the sum of the digits of a two-digit number for multiple test cases. Each input number $n$ is guaranteed to be between 10 and 99 inclusive, so the first digit is always nonzero.
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CF 1999C - Showering

We are given a day of length m minutes and a set of non-overlapping tasks, each occupying a continuous interval of time.
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CF 1999B - Card Game

We are asked to compute the number of ways Suneet can win a two-round card game against Slavic. Each player has exactly two cards, each numbered between 1 and 10.
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CF 1999A - A+B Again?

The task asks for the sum of the digits of a two-digit number for multiple test cases. Each input number $n$ is guaranteed to be between 10 and 99 inclusive, so the first digit is always nonzero.
codeforces competitive-programming implementation math Jun 8, 2026