C. Large GCD

Codeforces
IDCF10215C
Time1000ms
Memory256MB
Difficulty
English · Original
Formal · Original
This problem is very simple so the problem setters decided that its statement should be simple too. You are given two integers $n$ and $m$ such that $"gcd"(n, thin m) equiv 1$, and your task is to find the value of the function $"F"(n, thin m)$ as follows: In mathematics, the greatest common divisor (gcd) of two or more integers, which are not all zero, is the largest positive integer that divides each of the integers. For example, the gcd of $8$ and $12$ is $4$. The first line contains an integer $T$ ($1 <= T <= 10^5$) specifying the number of test cases. Each test case consists of a single line contains two integers $n$ and $m$ ($1 <= n, m <= 10^9, thin "gcd"(n, thin m) equiv 1$). For each test case, print a single line containing the value of the function $"F"(n, thin m)$ as described in the statement. In the first test case, the value of the function can be found as follow: $$\text{F}(2,\,3) = \text{gcd}(5^2 + 7^2,\,5^3 + 7^3)$$ $$\text{F}(2,\,3) = \text{gcd}(74,\, 468)$$ $$\text{F}(2,\,3) = 2$$ In the second test case, the value of the function can be found as follow: $$\text{F}(5,\,3) = \text{gcd}(5^5 + 7^5,\,5^3 + 7^3)$$ $$\text{F}(5,\,3) = \text{gcd}(19932,\, 468)$$ $$\text{F}(5,\,3) = 12$$ ## Input The first line contains an integer $T$ ($1 <= T <= 10^5$) specifying the number of test cases.Each test case consists of a single line contains two integers $n$ and $m$ ($1 <= n, m <= 10^9, thin "gcd"(n, thin m) equiv 1$). ## Output For each test case, print a single line containing the value of the function $"F"(n, thin m)$ as described in the statement. [samples] ## Note In the first test case, the value of the function can be found as follow: $$\text{F}(2,\,3) = \text{gcd}(5^2 + 7^2,\,5^3 + 7^3)$$ $$\text{F}(2,\,3) = \text{gcd}(74,\, 468)$$ $$\text{F}(2,\,3) = 2$$In the second test case, the value of the function can be found as follow: $$\text{F}(5,\,3) = \text{gcd}(5^5 + 7^5,\,5^3 + 7^3)$$ $$\text{F}(5,\,3) = \text{gcd}(19932,\, 468)$$ $$\text{F}(5,\,3) = 12$$
**Definitions** Let $ n \in \mathbb{Z} $ be the size of the array. Let $ A = (a_1, a_2, \dots, a_n) $ be a permutation of $ \{1, 2, \dots, n\} $. **Operation Definition** For a segment $ [L, R] $, the separation operation $ S(L, R) $ reorders the subarray $ (a_L, a_{L+1}, \dots, a_R) $ as follows: - Extract elements at odd offsets from $ L $: $ a_{L+1}, a_{L+3}, a_{L+5}, \dots $ (i.e., indices $ i $ where $ i - L $ is odd), preserving their relative order. - Append elements at even offsets from $ L $: $ a_L, a_{L+2}, a_{L+4}, \dots $ (i.e., indices $ i $ where $ i - L $ is even), preserving their relative order. The result replaces the original segment. **Constraints** 1. $ 1 \le n \le 3000 $ 2. $ a_i \in \{1, 2, \dots, n\} $, all distinct 3. Use at most $ 15000 $ separation operations **Objective** Find a sequence of operations $ S(L_1, R_1), S(L_2, R_2), \dots, S(L_k, R_k) $ with $ 0 \le k \le 15000 $, such that applying them in order transforms $ A $ into the sorted array $ (1, 2, \dots, n) $.
API Response (JSON)
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    "name": "C. Large GCD",
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      "content": "This problem is very simple so the problem setters decided that its statement should be simple too. You are given two integers $n$ and $m$ such that $\"gcd\"(n, thin m) equiv 1$, and your task is to fin",
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    "platform": "Codeforces",
    "limit": {
      "time_limit": 1000,
      "memory_limit": 262144
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    "difficulty": "None",
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