P9746 "KDOI-06-S" Merge Sequence

Given a sequence of length $n$, $a_1,a_2,\ldots a_n$. You may perform several (possibly $0$) operations on this sequence. In each operation, you will: * Choose three positive integers $i

Read input from standard input. **This problem contains multiple test cases.** The first line contains a positive integer $T$, indicating the number of test cases. For each test case, the first line contains a positive integer $n$, indicating the initial length of the sequence. The second line contains $n$ integers $a_1,a_2,\ldots,a_n$, indicating the value of each element in the initial sequence.

For each test case: + If there exists a plan such that the sequence $a$ is reduced to only one number, output `Huoyu` on the first line. + Then, on the second line output a non-negative integer $t$, indicating the number of operations. You need to ensure $0\le t\le n$. + Then output $t$ lines, each containing three positive integers $i,j,k$, indicating the three numbers you choose in this operation. You need to ensure $i

**[Sample Explanation #1]** For the first test case: * In the first operation, $a_3\oplus a_4\oplus a_5=1\oplus4\oplus5=0$, and the sequence becomes $[3,3,0]$ after the operation. * In the second operation, $a_1\oplus a_2\oplus a_3=3\oplus3\oplus0=0$, and the sequence becomes $[0]$ after the operation. Thus, after two operations, the sequence $a$ contains only one number. For the second test case: * In the first operation, $a_1\oplus a_3\oplus a_4=3\oplus6\oplus5=0$, $s=4$, and the sequence becomes $[4,4,5,1,2,4]$ after the operation. * In the second operation, $a_2\oplus a_3\oplus a_4=4\oplus5\oplus1=0$, and the sequence becomes $[4,0,2,4]$ after the operation. * In the third operation, $a_1\oplus a_2\oplus a_4=4\oplus0\oplus4=0$, $s=2$, and the sequence becomes $[2]$ after the operation. Thus, after three operations, the sequence $a$ contains only one number. **[Sample #2]** See `merge/merge2.in` and `merge/merge2.ans` under the contestant directory. This sample satisfies the constraints of test points $6\sim7$. **[Sample #3]** See `merge/merge3.in` and `merge/merge3.ans` under the contestant directory. This sample satisfies the constraints of test points $12\sim13$. **[Constraints]** For all testdata, it is guaranteed that: $1\leq T\leq20$, $1\leq n\leq500$, $0\leq a_i