Binary Search Tree analog

Input

The first integer of the input is T, the number of test cases.
Each test case has two lines.
The first line contain an integer N,(1<=N<=1000), the number of numbers need to be inserted into the BST.
The second line contain N integers separated by space, each integer is in the range of [0,230].

Output

Each test case, output must contain three lines: the preorder, inorder and postorder traversal
sequence. The numbers in each line should be separated by a single space and you should not output anything at the end of the line! Output a blank line after each case.

Sample Input

1
5
3 6 9 5 1

Sample Output

3 1 6 5 9
1 3 5 6 9
1 5 9 6 3

HINT

#include <stdio.h>

#define N 1000

struct node

{

int x;

struct node *left,*right;

}node
;

char f;

void Insert(struct node *r,struct node *p)

{

if(!r) return;

if(r->x>p->x)

{

if(r->left) Insert(r->left,p);

else r->left=p;

}

else

{

if(r->right) Insert(r->right,p);

else r->right=p;

}

}

void pretral(struct node *p)

{

if(!p) return;

if(f) printf("%d",p->x),f=0;

else printf(" %d",p->x);

pretral(p->left);

pretral(p->right);

}

void intral(struct node *p)

{

if(!p) return;

intral(p->left);

if(f) printf("%d",p->x),f=0;

else printf(" %d",p->x);

intral(p->right);

}

void postod(struct node *p)

{

if(!p) return;

postod(p->left);

postod(p->right);

if(f) printf("%d",p->x),f=0;

else printf(" %d",p->x);

}

int main()

{

int t,i,n,x;

struct node root;

struct node *p;

scanf("%d",&t);

while(t--)

{

scanf("%d",&n);

scanf("%d",&root.x);

root.left=root.right=0;

for(i=0;i<n-1;i++)

{

scanf("%d",&x);

p=&node[i];

p->x=x;

p->left=p->right=0;

Insert(&root,p);

}

f=1;

pretral(&root);

printf("\n");

f=1;

intral(&root);

printf("\n");

f=1;

postod(&root);

printf("\n");

printf("\n");

}

return 0;

}