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PRIME - MarisaOJ: Marisa Online Judge

PRIME

Time limit: 1000 ms
Memory limit: 256 MB
Given an array of $n$ positive integers $a_1, a_2, \ldots, a_n$. You can perform the following operation any number of times: - Increase or decrease any element $a_i$ by 1, as long as the element remains a positive integer ($a_i \ge 1$). Find the minimum number of operations required such that the product of all elements in the array becomes a power of a prime number. That is, $\prod_{i=1}^n a_i = p^k$, where $p$ is a prime number and $k$ is a non-negative integer. #### Input - The first line contains an integer $n$ ($1 \leq n \leq 10^5$). - The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ($1 \leq a_i \leq 10^7$). #### Output - Output a single integer, the minimum number of operations required. #### Subtasks - **Subtask 1 (10%):** $n = 1$. - **Subtask 2 (20%):** $n \le 5$ and $a_i \le 20$. - **Subtask 3 (30%):** $n \le 1000$ and $a_i \le 1000$. - **Subtask 4 (20%):** $a_i \le 3$. - **Subtask 5 (10%):** $a_i \le 10^5$. - **Subtask 6 (10%):** $a_i \le 10^7$. #### Example Input: ``` 3 3 5 8 ``` Output: ``` 2 ``` Explanation: We can change the array to $[2, 4, 8]$ (product $64 = 2^6$). - Change $3 \to 2$ (1 op) - Change $5 \to 4$ (1 op) - $8$ remains $8$ (0 ops) Total operations: 2. Target prime $p=2$.
PTNK Prelimination - [2025-2026]
PRIME
TOURIST
TRANSPORT
Topic
2026
Rating 800
Source PTNK
Solution (1) Solution