Codeforces Round 790 (Div. 4)

Solutions for Codeforces Round 790 (Div. 4) (contest 1676). 9/9 problems verified against sample I/O. Difficulty range: 800-1500.

9 items

Codeforces Round 790 (Div. 4)

Type: Div. 4 | Problems: 9 | Verified: 9/9 | Rating range: 800-1500 | Time: 19m

Problem	Name	Rating	Tags	Solve Time	Verified
A	Lucky?	800	implementation	1m 35s	✓
B	Equal Candies	800	greedy, math, sortings	5m 37s	✓
C	Most Similar Words	800	brute-force, greedy, implementation	1m 51s	✓
D	X-Sum	1000	brute-force, greedy, implementation	1m 47s	✓
E	Eating Queries	1100	binary-search, greedy, sortings	1m 25s	✓
F	Longest Strike	1300	data-structures, greedy, implementation	1m 35s	✓
G	White-Black Balanced Subtrees	1300	dfs-and-similar, dp, graphs	1m 39s	✓
H1	Maximum Crossings (Easy Version)	1400	brute-force	1m 51s	✓
H2	Maximum Crossings (Hard Version)	1500	data-structures, divide-and-conquer, sortings	1m 40s	✓

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676H1 - Maximum Crossings (Easy Version)

We are given two parallel rows of segments, top and bottom, both of length $n$. Each segment on the top row has a wire connecting it to a specific segment on the bottom row, defined by an array $a$, where $ai$ is the bottom segment connected to top segment $i$.

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676H2 - Maximum Crossings (Hard Version)

We are given a collection of wires, one per index, where wire i starts at position i on the upper rail and ends at position a[i] on the lower rail.

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676B - Equal Candies

We are given a set of boxes, each containing some number of candies. There is exactly one box for each friend, and the goal is to make all boxes contain the same number of candies so that no friend feels left out. We can only eat candies from a box; we cannot add any.

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676G - White-Black Balanced Subtrees

We are given a rooted tree where vertex 1 is the root. Every vertex is colored either black or white. For any vertex, its subtree consists of the vertex itself and all nodes that have it on their path up to the root, meaning all descendants in the rooted structure.

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676F - Longest Strike

We are given an array of integers and a threshold number $k$. Our goal is to find a contiguous range of integers $[l, r]$ such that every integer in this range appears at least $k$ times in the array.

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676D - X-Sum

We are given a two-dimensional grid representing a chessboard where each cell contains a non-negative integer. A bishop can be placed on any cell, and it attacks all cells along the four diagonals that intersect at its position. The cell the bishop occupies counts as attacked.

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676E - Eating Queries

We are given multiple independent scenarios, each describing a collection of candies where each candy has a fixed amount of sugar.

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676C - Most Similar Words

We are given a collection of words where each word has the same length. Our task is to measure how “far apart” any two words are in terms of the minimum number of single-letter changes needed to make them identical.

Practice › Codeforces Solutions › Codeforces Round 790 (Div. 4) ›

CF 1676A - Lucky?

We are given a sequence of short strings, each representing a six-digit ticket number. Each ticket should be split into two halves of equal length. The task is to decide whether the sum of digits in the left half matches the sum of digits in the right half.