Surprise Language Round 7

Solutions for Surprise Language Round 7 (contest 470). 8/8 problems verified against sample I/O. Difficulty range: 1400-2300.

8 items

Surprise Language Round 7

Type: Special | Problems: 8 | Verified: 8/8 | Rating range: 1400-2300 | Time: 10m 9s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Crystal Ball Sequence	1400	*special, implementation	1m 36s	✓
B	Hexakosioihexekontahexaphobia	1800	*special	1m 6s	✓
C	Eval	1900	*special	1m 2s	✓
D	Caesar Cipher	1900	*special	1m 24s	✓
E	Chessboard	1900	*special	1m 29s	✓
F	Pairwise Sums	2300	*special	1m 17s	✓
G	Hamming Distance	2300	*special	57s	✓
H	Array Sorting	2300	*special	1m 18s	✓

Practice › Codeforces Solutions › Surprise Language Round 7 ›

CF 470A - Crystal Ball Sequence

The sequence in this problem comes from counting lattice points inside a growing hexagon on a hexagonal grid. Instead of having to construct the hexagon or count points manually, the problem already gives the formula for the sequence: $$Hn = 3 cdot n cdot (n+1) + 1$$ The input…

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CF 470B - Hexakosioihexekontahexaphobia

We are given a string consisting solely of digits, and the task is to determine if the number "666" appears anywhere as a contiguous sequence inside that string. The output should be "YES" if it does, and "NO" otherwise.

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CF 470C - Eval

The task is to evaluate a simple arithmetic expression of the form a?b where a and b are integers between 1 and 999, and ? is a single operator from the set +, -, , /, or %.

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CF 470D - Caesar Cipher

We are asked to implement a simple Caesar cipher. The input gives us a key k, an integer between 0 and 25, which represents how many positions each letter in the message should be shifted forward in the alphabet.

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CF 470E - Chessboard

We need to print an n × n chessboard using characters. White squares are represented by . and black squares by . The square in the top-left corner is white, and colors alternate both horizontally and vertically exactly as on a real chessboard.

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CF 470F - Pairwise Sums

The problem asks us to take a list of integers and, for each element, produce the sum of that element with the element immediately preceding it. The twist is that the first element of the output pairs with the last element of the array, creating a circular relationship.

Practice › Codeforces Solutions › Surprise Language Round 7 ›

CF 470G - Hamming Distance

The task is to compute the Hamming distance between two strings of equal length. In practical terms, you are comparing two sequences of letters and counting how many positions contain different characters. Each mismatch contributes exactly one to the distance.

Practice › Codeforces Solutions › Surprise Language Round 7 ›

CF 470H - Array Sorting

We are given an array of integers. The first number in the input is the array size n, and the next n integers are the array elements. The task is simply to output the same elements arranged in non-decreasing order.