Description
In this problem, you are to implement a binary search tree
with insert only operation
That is, insert a1,a2,...,an in order
Finally, output the preorder of the BST
Input
The first line is an integer T, the number of testcases.
For each testcase:
The first line is an integer n , the number of numbers to be inserted
The second line n positive integers a1,a2,...,an （numbers are distinct）
n, ai<=1000
Output
輸出一行以空白隔開BST的preorder 行末不要空白
Example:
for(i=0; i<100; i++){
if(0<i)printf(" ");
printf("%d",num[i]);
}
printf("\n");