Codeforces Round 799 (Div. 4)

Solutions for Codeforces Round 799 (Div. 4) (contest 1692). 6/8 problems verified against sample I/O. Difficulty range: 800-1700.

8 items

Codeforces Round 799 (Div. 4)

Type: Div. 4 | Problems: 8 | Verified: 6/8 | Rating range: 800-1700 | Time: 16m 52s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Marathon	800	implementation	1m 48s	✓
B	All Distinct	800	greedy, sortings	2m 19s	✓
C	Where's the Bishop?	800	implementation	1m 44s	✗
D	The Clock	1100	brute-force, implementation	2m 35s	✓
E	Binary Deque	1200	binary-search, implementation, two-pointers	1m 50s	✓
F	3SUM	1300	brute-force, math	1m 57s	✓
G	2^Sort	1400	data-structures, dp, sortings	1m 33s	✓
H	Gambling	1700	data-structures, dp, greedy	3m 6s	✗

Practice › Codeforces Solutions › Codeforces Round 799 (Div. 4) ›

CF 1692H - Gambling

We know the outcomes of the next $n$ dice rolls in advance. Marian chooses a value $a$, and a contiguous segment of rounds $[l,r]$. During every round in that segment he always guesses the same value $a$. Whenever the actual rolled value equals $a$, his money doubles.

Practice › Codeforces Solutions › Codeforces Round 799 (Div. 4) ›

CF 1692G - 2^Sort

We are given an array and asked to examine every contiguous segment of fixed length $k+1$. For each such segment starting at position $i$, we conceptually transform it by multiplying element $j$ (relative to the segment start) by $2^j$.

Practice › Codeforces Solutions › Codeforces Round 799 (Div. 4) ›

CF 1692D - The Clock

We are given a starting time on a 24-hour clock and a fixed number of minutes between observations. Starting from the given time, Victor repeatedly looks at the clock after every $x$ minutes.

Practice › Codeforces Solutions › Codeforces Round 799 (Div. 4) ›

CF 1692F - 3SUM

We are given an array of positive integers, and we want to know if we can select three distinct elements whose sum ends with the digit 3. In other words, if we denote the chosen elements as $ai$, $aj$, and $ak$, then $(ai + aj + ak) mod 10 = 3$.

Practice › Codeforces Solutions › Codeforces Round 799 (Div. 4) ›

CF 1692E - Binary Deque

We are given a binary array of length $n$, meaning each element is either 0 or 1. The task is to perform a sequence of operations where, in each operation, we remove either the first or the last element of the array.

Practice › Codeforces Solutions › Codeforces Round 799 (Div. 4) ›

CF 1692B - All Distinct

We are given an array of integers. In one operation, we must remove exactly two elements from the array. The two removed elements can be any values, as long as they come from different positions.

Practice › Codeforces Solutions › Codeforces Round 799 (Div. 4) ›

CF 1692A - Marathon

We are asked to determine Timur's position relative to three other runners in a marathon. Each test case provides four distinct integers: Timur's distance first, followed by the distances run by three other participants.

Practice › Codeforces Solutions › Codeforces Round 799 (Div. 4) ›

CF 1692C - Where's the Bishop?

The discrepancy is not caused by a small implementation bug. The outputs show that the algorithm itself is overcounting the cost of independent intervals.