计算二叉树指定结点p的层数(设树根为第一层)

计算二叉树指定结点p的层数(设树根为第一层)

int level(struct node *t,struct node *p) {
return t ? _level(t, p, 1) : 0;
}

int __level(struct node *cur, struct node *goal, int depth) {
if (cur == NULL) return 0;
if (cur == goal) return depth;
int l = __level(cur->left, goal, depth + 1);
if (l > 0) return l;
int r = __level(cur->right, goal, depth + 1);
if (r > 0) return r;
return -1
}