遍历二叉树

打基础赛但是忘了怎么遍历了于是赛后写板子

struct __
{
	char data;
	int lch, rch;
}tr[maxn];
int n = 0;
void preorder(int rt)
{
	printf("%c", tr[rt].data);
	if(tr[rt].lch) preorder(tr[rt].lch);
	if(tr[rt].rch) preorder(tr[rt].rch);
}
void inorder(int rt)
{ 
	if(tr[rt].lch) inorder(tr[rt].lch);
	printf("%c", tr[rt].data);
	if(tr[rt].rch) inorder(tr[rt].rch);	
}
void postorder(int rt)
{
	if(tr[rt].lch) postorder(tr[rt].lch);
	if(tr[rt].rch) postorder(tr[rt].rch);	
	printf("%c", tr[rt].data);	
}