Codeforces Round 731 (Div. 3)

7 problems from Codeforces Round 731 (Div. 3) (contest 1547), difficulty 800-2100. 2/7 solutions verified against sample I/O.

7 items

Codeforces Round 731 (Div. 3)

Div. 3 | 7 problems | 2/7 verified | Difficulty 800-2100 | 52m 52s

# Problem Rating Tags Accepted Time ✓
A Shortest Path with Obstacle 800 implementation, math 32,287 7m 40s ✓
B Alphabetical Strings 800 greedy, implementation, strings 27,889 8m 37s
C Pair Programming 1100 greedy, two-pointers 24,412 9m 7s
D Co-growing Sequence 1300 bitmasks, constructive-algorithms, greedy 18,586 8m 23s
E Air Conditioners 1500 data-structures, dp, implementation 16,372 7m 45s
F Array Stabilization (GCD version) 1900 binary-search, brute-force, data-structures 6,943 2m 26s ✓
G How Many Paths? 2100 dfs-and-similar, dp, graphs 3,545 8m 54s
Practice › Codeforces Solutions › Codeforces Round 731 (Div. 3) ›

CF 1547G - How Many Paths?

We are given a directed graph where we start from node 1 and consider all possible directed walks that end at each vertex. A walk can revisit nodes and edges arbitrarily many times.
codeforces competitive-programming dfs-and-similar dp graphs trees Jun 14, 2026
Practice › Codeforces Solutions › Codeforces Round 731 (Div. 3) ›

CF 1547E - Air Conditioners

We are given a one-dimensional strip of length $n$. Some positions on this strip contain air conditioners, each fixed at a known coordinate and each producing its own base temperature.
codeforces competitive-programming data-structures dp implementation shortest-paths sortings two-pointers Jun 14, 2026
Practice › Codeforces Solutions › Codeforces Round 731 (Div. 3) ›

CF 1547D - Co-growing Sequence

We are given a sequence $x1, x2, dots, xn$. Our task is to construct another sequence $y1, y2, dots, yn$ such that when we XOR them elementwise, the resulting sequence $$ai = xi oplus yi$$ has a monotone bit-structure: every bit that is set in $ai$ must also be set in $a{i+1}$.
codeforces competitive-programming bitmasks constructive-algorithms greedy Jun 14, 2026
Practice › Codeforces Solutions › Codeforces Round 731 (Div. 3) ›

CF 1547C - Pair Programming

Two programmers are contributing edits to the same file, but their work histories are interleaved in time. We are given two ordered sequences of actions, one for each person. Each action is either an insertion at the end of the file or an edit of an existing line.
codeforces competitive-programming greedy two-pointers Jun 14, 2026
Practice › Codeforces Solutions › Codeforces Round 731 (Div. 3) ›

CF 1547B - Alphabetical Strings

We are given a string and we need to decide whether it could have been constructed by a very specific process that builds strings from left to right choices.
codeforces competitive-programming greedy implementation strings Jun 14, 2026
Practice › Codeforces Solutions › Codeforces Round 731 (Div. 3) ›

CF 1547A - Shortest Path with Obstacle

We are working on an infinite grid where movement is allowed in four directions: up, down, left, and right, each costing one step. We are given three special cells: a start cell, a target cell, and a forbidden cell that cannot be stepped on.
codeforces competitive-programming implementation math Jun 14, 2026
Practice › Codeforces Solutions › Codeforces Round 731 (Div. 3) ›

CF 1547F - Array Stabilization (GCD version)

We are given a circular array of positive integers. In each step, we replace every element with the greatest common divisor of itself and its right neighbor, wrapping around at the end.
codeforces competitive-programming binary-search brute-force data-structures divide-and-conquer number-theory two-pointers Jun 10, 2026