P7285 "EZEC-5" Modify the Array

Given an array of length $n$ whose elements are $0$ or $1$. Now you may **choose some (possibly $0$) elements with value $0$ and change them to $1$**. Let: - $x$ be the length of the longest consecutive subarray of $1$s (by definition, if all numbers are $0$, then $x = 0$); - $y$ be the number of modified elements. Find how to modify the array to maximize $x - y$, and construct one valid plan (output the modified array).

**This problem contains multiple test cases.** The first line contains an integer $T$ indicating the number of test cases. The next $2 \times T$ lines describe the test cases, where every $2$ lines correspond to one test case. In each test case, the first line contains an integer $n$, the length of the array. The second line contains $n$ integers ($0$ or $1$), representing the given array.

Output a total of $2 \times T$ lines, where every $2$ lines correspond to one test case. In each test case, on the first line output an integer, the maximum value of $x - y$. On the second line output $n$ integers ($0$ or $1$), representing the modified array. **If there are multiple solutions, output any one of them.**

**This problem uses bundled tests.** For all testdata, it is guaranteed that $T \le 10$ and $1 \le n \le 10^5$, and the array elements $\in \{0,1\}$. - Subtask 1 (70 points): $1 \le n \le 10$. - Subtask 2 (30 points): no additional constraints. Translated by ChatGPT 5