Codeforces Round 677 (Div. 3)

Solutions for Codeforces Round 677 (Div. 3) (contest 1433). 3/7 problems verified against sample I/O. Difficulty range: 800-2100.

7 items

Codeforces Round 677 (Div. 3)

Type: Div. 3 | Problems: 7 | Verified: 3/7 | Rating range: 800-2100 | Time: 19m 11s

Problem Name Rating Tags Solve Time Verified
A Boring Apartments 800 implementation, math 2m 40s ✗
B Yet Another Bookshelf 800 greedy, implementation 1m 30s ✓
C Dominant Piranha 900 constructive-algorithms, greedy 8m 25s ✗
D Districts Connection 1200 constructive-algorithms, dfs-and-similar 1m 28s ✗
E Two Round Dances 1300 combinatorics, math 2m 32s ✗
F Zero Remainder Sum 2100 dp 1m 29s ✓
G Reducing Delivery Cost 2100 brute-force, graphs, shortest-paths 1m 7s ✓
Practice › Codeforces Solutions › Codeforces Round 677 (Div. 3) ›

CF 1433C - Dominant Piranha

We are asked to identify a dominant piranha in a linear aquarium. Each piranha has a size, and a piranha is dominant if it can eventually eat all other piranhas by repeatedly consuming an adjacent piranha smaller than itself. Every time it eats, its size increases by one.
codeforces competitive-programming constructive-algorithms greedy Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 677 (Div. 3) ›

CF 1433G - Reducing Delivery Cost

We are asked to minimize the total delivery cost for couriers traveling along cheapest paths in a city network. The city is modeled as an undirected weighted graph with n districts as nodes and m two-way roads as edges, each with a positive cost.
codeforces competitive-programming brute-force graphs shortest-paths Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 677 (Div. 3) ›

CF 1433E - Two Round Dances

The key issue is that this is a constructive problem. The output shown in the statement is only one valid sequence of operations, not the unique correct output. Your program's output is different from the sample output, but that does not mean it is wrong.
codeforces competitive-programming combinatorics math Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 677 (Div. 3) ›

CF 1433F - Zero Remainder Sum

We are given a grid of numbers with $n$ rows and $m$ columns. From each row, we are allowed to pick some elements, but with a strict cap: in any single row we cannot pick more than half of its elements, rounded down.
codeforces competitive-programming dp Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 677 (Div. 3) ›

CF 1433D - Districts Connection

We are given several independent scenarios. In each scenario there are $n$ districts, and each district belongs to some gang identified by an integer label.
codeforces competitive-programming constructive-algorithms dfs-and-similar Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 677 (Div. 3) ›

CF 1433A - Boring Apartments

The key issue is that this is a constructive problem. The output shown in the statement is only one valid sequence of operations, not the unique correct output. Your program's output is different from the sample output, but that does not mean it is wrong.
codeforces competitive-programming implementation math Jun 11, 2026
Practice › Codeforces Solutions › Codeforces Round 677 (Div. 3) ›

CF 1433B - Yet Another Bookshelf

We are given a bookshelf represented as a binary array. A value of 1 means a book is present at that position, while 0 means the position is empty.
codeforces competitive-programming greedy implementation Jun 11, 2026