PE: 行末不留空格 BST 插入与遍历

PE了一早上——就是因为行末空格的问题

想过用链表在遍历过程中存储节点，然后打印；

想过用静态变量保存；

最后，回到了指针，传递计数器的地址。

//1005 BST 建树、遍历
# include <stdio.h>
# include <stdlib.h>

typedef struct Tnode{
    int key;
    struct Tnode *left;
    struct Tnode *right;
}node;

node *BST_insert(node *root, node *p);
void preorder(node *x, int *p);
void inorder(node *x, int *p);
void aftorder(node *x, int *p);

int main()
{
    int T, n, cnt, tmp;
    node *p, *root;
    scanf("%d", &T);
    while (T > 0)
    {
        root = NULL;
        scanf("%d", &n);
        tmp = cnt = n;
        while (n > 0)
        {
            p = (node *)malloc(sizeof(node));
            p->left = p->right = NULL;
            scanf("%d", &p->key);
            root = BST_insert(root, p);
            --n;
        }
        preorder(root,&cnt);
        printf("\n");
        cnt = tmp;
        inorder(root,&cnt);
        printf("\n");
        cnt = tmp;
        aftorder(root,&cnt);
        printf("\n\n");
        --T;
    }
    return 0;
}

node *BST_insert(node *root, node *p)
{
    node *x, *y;
    y = NULL;
    x = root;
    while (x != NULL)
    {
        y = x;
        if (p->key < x->key) x = x->left;
        else x = x->right;
    }
    if (y == NULL) root = p;
    else if (p->key < y->key)
        y->left = p;
    else y->right = p;
    return root;
}
void preorder(node *x, int *p)
{
    if (x != NULL)
    {
        printf(((*p)==1 ? "%d":"%d "), x->key);
        --(*p);
        preorder(x->left, p);
        preorder(x->right, p);
    }
}
void inorder(node *x, int *p)
{
    if (x != NULL)
    {
        inorder(x->left, p);
        printf(((*p)==1 ? "%d":"%d "), x->key);
        --(*p);
        inorder(x->right, p);
    }
}
void aftorder(node *x, int *p)
{
    if (x != NULL)
    {
        aftorder(x->left, p);
        aftorder(x->right, p);
        printf(((*p)==1 ? "%d":"%d "), x->key);
        --(*p);
    }
}

欢迎、谢谢大牛的指正！