Codeforces Round 676 (Div. 2)

Solutions for Codeforces Round 676 (Div. 2) (contest 1421). 4/5 problems verified against sample I/O. Difficulty range: 800-2700.

5 items

Codeforces Round 676 (Div. 2)

Type: Div. 2 | Problems: 5 | Verified: 4/5 | Rating range: 800-2700 | Time: 23m 51s

Problem	Name	Rating	Tags	Solve Time	Verified
A	XORwice	800	bitmasks, greedy, math	10m 16s	✓
B	Putting Bricks in the Wall	1100	constructive-algorithms, implementation	1m 41s	✓
C	Palindromifier	1400	constructive-algorithms, strings	8m 21s	✓
D	Hexagons	1900	brute-force, constructive-algorithms, greedy	2m 5s	✗
E	Swedish Heroes	2700	brute-force, dp, implementation	1m 28s	✓

Practice › Codeforces Solutions › Codeforces Round 676 (Div. 2) ›

CF 1421A - XORwice

The problem asks for the minimum sum of two XOR operations for a pair of integers a and b when XORed with the same number x. Concretely, given a and b, we must choose x such that the expression (a XOR x) + (b XOR x) is as small as possible.

Practice › Codeforces Solutions › Codeforces Round 676 (Div. 2) ›

CF 1421C - Palindromifier

The failure you show is not actually an algorithmic failure. The traceback: means the test harness tried to execute: but the submitted file did not contain a function named solve. This happens before any input is processed, so there is no way to trace the algorithm on abac.

Practice › Codeforces Solutions › Codeforces Round 676 (Div. 2) ›

CF 1421E - Swedish Heroes

We are given a lineup of heroes, each with a numeric power. The only allowed operation is to select two consecutive heroes, remove them, and insert a single new hero whose power is the negative of their sum.

Practice › Codeforces Solutions › Codeforces Round 676 (Div. 2) ›

CF 1421D - Hexagons

We are working on a hexagonal grid where each cell has six possible neighboring cells, one in each direction of the hexagon layout. Moving from any cell to an adjacent one has a fixed cost depending only on the direction of the move, not on the position of the cell.

Practice › Codeforces Solutions › Codeforces Round 676 (Div. 2) ›

CF 1421B - Putting Bricks in the Wall

We are given a square grid of size $n times n$ representing a room. Each cell contains either a 0 or 1, except the start at the top-left and finish at the bottom-right, which are labeled 'S' and 'F'.