Codeforces Round 811 (Div. 3)

Solutions for Codeforces Round 811 (Div. 3) (contest 1714). 2/7 problems verified against sample I/O. Difficulty range: 800-1900.

7 items

Codeforces Round 811 (Div. 3)

Type: Div. 3 | Problems: 7 | Verified: 2/7 | Rating range: 800-1900 | Time: 20m 13s

Problem Name Rating Tags Solve Time Verified
A Everyone Loves to Sleep 900 implementation, math 7m 20s ✗
B Remove Prefix 800 data-structures, greedy, implementation 1m 39s ✓
C Minimum Varied Number 800 greedy 1m 32s ✓
D Color with Occurrences 1600 brute-force, data-structures, dp 2m 23s ✗
E Add Modulo 10 1400 brute-force, math, number-theory 2m 27s ✗
F Build a Tree and That Is It 1900 constructive-algorithms, implementation, trees 2m 41s ✗
G Path Prefixes 1700 binary-search, data-structures, dfs-and-similar 2m 11s ✗
Practice › Codeforces Solutions › Codeforces Round 811 (Div. 3) ›

CF 1714A - Everyone Loves to Sleep

The intended structure of the solution was: 1. Run shortest paths using roads (standard Dijkstra). 2. Repeatedly allow up to k flights. 3. Each flight step computes: $$new[v] = minu (dp[u] + (u - v)^2)$$ 4. Then relax roads again.
codeforces competitive-programming implementation math Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 811 (Div. 3) ›

CF 1714F - Build a Tree and That Is It

We are asked to construct an unrooted tree with a fixed number of vertices and three specific distance constraints between vertices 1, 2, and 3. Each test case provides four integers: the number of nodes $n$ and the pairwise distances $d{12}$, $d{23}$, and $d{31}$.
codeforces competitive-programming constructive-algorithms implementation trees Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 811 (Div. 3) ›

CF 1714G - Path Prefixes

We are asked to process a rooted tree with values on each edge. Each edge has two integers, $aj$ and $bj$. For every non-root node $i$, we consider the path from the root to $i$. Let $Ai$ be the sum of all $aj$ along this path.
codeforces competitive-programming binary-search data-structures dfs-and-similar trees Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 811 (Div. 3) ›

CF 1714E - Add Modulo 10

We are given an array of integers, and for each element we can repeatedly increase it by its last digit. For instance, if the element is 27, applying the operation gives 27 + 7 = 34, and applying it again gives 34 + 4 = 38.
codeforces competitive-programming brute-force math number-theory Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 811 (Div. 3) ›

CF 1714D - Color with Occurrences

We are given a target string t and up to ten pattern strings. A move consists of picking one pattern and choosing one of its occurrences inside t, then marking all characters of that occurrence as colored.
codeforces competitive-programming brute-force data-structures dp greedy strings Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 811 (Div. 3) ›

CF 1714B - Remove Prefix

We are given a sequence of integers a of length n, where each integer lies between 1 and n. The goal is to make the sequence contain only distinct values by repeatedly removing elements from the beginning.
codeforces competitive-programming data-structures greedy implementation Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 811 (Div. 3) ›

CF 1714C - Minimum Varied Number

We are given a target sum for digits, and for each query we need to construct the smallest possible positive integer whose digits are all different and whose digit sum equals that target.
codeforces competitive-programming greedy Jun 9, 2026