Codeforces Round 830 (Div. 2)

7 problems from Codeforces Round 830 (Div. 2) (contest 1732), difficulty 900-2800. 4/7 solutions verified against sample I/O.

7 items

Codeforces Round 830 (Div. 2)

Div. 2 | 7 problems | 4/7 verified | Difficulty 900-2800 | 38m 19s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Bestie	1000	brute-force, combinatorics, constructive-algorithms	17,533	8m 55s	✓
B	Ugu	900	brute-force, dp, greedy	17,256	4m 53s	✓
C1	Sheikh (Easy version)	1800	binary-search, bitmasks, greedy	7,564	2m 46s	✓
C2	Sheikh (Hard Version)	2100	binary-search, bitmasks, brute-force	3,067	4m
D1	Balance (Easy version)	1500	brute-force, data-structures, implementation	9,901	2m 56s	✓
D2	Balance (Hard version)	2400	brute-force, data-structures, number-theory	1,591	7m 24s
E	Location	2800	data-structures, dp, math	583	7m 25s

Practice › Codeforces Solutions › Codeforces Round 830 (Div. 2) ›

CF 1732E - Location

Each position in the array behaves like a pair of values, a dynamic value $ai$ and a fixed value $bi$. Over time, we repeatedly overwrite entire segments of the $a$-array with a single number, and occasionally we are asked to inspect a segment and find the smallest value of a…

Practice › Codeforces Solutions › Codeforces Round 830 (Div. 2) ›

CF 1732D2 - Balance (Hard version)

We maintain a dynamic set of non-negative integers. It starts with a single element, zero, and evolves through three types of operations: insert a new number, delete an existing number, and answer a query that depends on a parameter $k$.

Practice › Codeforces Solutions › Codeforces Round 830 (Div. 2) ›

CF 1732D1 - Balance (Easy version)

We start with a set that initially contains only the number zero. Over time, two kinds of operations are applied. One operation inserts a new integer into the set, and the other asks a query about a special value called the k-mex.

Practice › Codeforces Solutions › Codeforces Round 830 (Div. 2) ›

CF 1732B - Ugu

We are given a binary string, and we want to transform it into a non-decreasing sequence, meaning that once the string starts containing 1, it should never go back to 0. The final form must look like some number of 0s followed by some number of 1s.

Practice › Codeforces Solutions › Codeforces Round 830 (Div. 2) ›

CF 1732C2 - Sheikh (Hard Version)

We are given an array and multiple range queries. For each query interval, we must choose a contiguous subarray fully inside that interval and maximize a score defined on that subarray.

Practice › Codeforces Solutions › Codeforces Round 830 (Div. 2) ›

CF 1732C1 - Sheikh (Easy version)

We are given an array and we are allowed to choose any contiguous segment inside it. For each segment, we compute a score defined as the difference between its sum and its bitwise XOR.

Practice › Codeforces Solutions › Codeforces Round 830 (Div. 2) ›

CF 1732A - Bestie

We are given an array of integers. We may repeatedly choose an index $i$ and replace $ai$ by $gcd(ai, i)$. Performing this operation costs $n-i+1$, so operations on positions near the end of the array are cheaper.