Codeforces Beta Round 72 (Div. 1 Only)

Solutions for Codeforces Beta Round 72 (Div. 1 Only) (contest 83). 5/5 problems verified against sample I/O. Difficulty range: 1300-2800.

5 items

Codeforces Beta Round 72 (Div. 1 Only)

Type: Div. 1 | Problems: 5 | Verified: 5/5 | Rating range: 1300-2800 | Time: 9m 17s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Magical Array	1300	math	1m 28s	✓
B	Doctor	1800	binary-search, math, sortings	1m 37s	✓
C	Track	2400	graphs, greedy, shortest-paths	2m 22s	✓
D	Numbers	2400	dp, math, number-theory	2m 7s	✓
E	Two Subsequences	2800	bitmasks, dp	1m 43s	✓

Practice › Codeforces Solutions › Codeforces Beta Round 72 (Div. 1 Only) ›

CF 83A - Magical Array

We are given an integer array and need to count how many contiguous subarrays are "magical". A subarray is magical when its minimum value is equal to its maximum value. A minimum and maximum can only be equal if every element inside the subarray is the same.

Practice › Codeforces Solutions › Codeforces Beta Round 72 (Div. 1 Only) ›

CF 83B - Doctor

We have a queue of animals waiting for the doctor. Animal i must visit the doctor exactly a[i] times before leaving forever. Whenever an animal is examined, one of two things happens. If it still needs more visits, it immediately moves to the back of the queue.

Practice › Codeforces Solutions › Codeforces Beta Round 72 (Div. 1 Only) ›

CF 83C - Track

We have a rectangular grid. Each cell contains either a terrain type represented by a lowercase letter, the start cell S, or the target cell T. We may move in four directions between side-adjacent cells. Every move costs exactly one minute. The path must start at S and end at T.

Practice › Codeforces Solutions › Codeforces Beta Round 72 (Div. 1 Only) ›

CF 83D - Numbers

We need to count integers inside the interval $[a,b]$ whose smallest divisor greater than $1$ is exactly $k$. For a number $x$, saying that its smallest divisor is $k$ means two things happen simultaneously: 1. $x$ is divisible by $k$. 2.

Practice › Codeforces Solutions › Codeforces Beta Round 72 (Div. 1 Only) ›

CF 83E - Two Subsequences

We are given a sequence of binary strings, all of equal length, and we need to split them into two subsequences in a way that minimizes the sum of the lengths of their compressed forms.