20pts神秘错误

#include <bits/stdc++.h>
using namespace std;
struct node{
    node* lchild;
    node* rchild;
    int num;
};
int k,ans;
node* head;
void deep(int d,node* h){
    if(h->lchild!=NULL)deep(d+1,h->lchild);
    if(h->rchild!=NULL)deep(d+1,h->rchild);
    ans=max(ans,d);
    return;
}
void push(int x,node* h){
    if(h->lchild!=NULL&&x<h->num){
        push(x,h->lchild);
        return;
    }
    if(h->rchild!=NULL){
        push(x,h->rchild);
        return;
    }
    node* t=new node;
    t->lchild=t->rchild=NULL;
    t->num=x;
    if(x<h->num)h->lchild=t;
    else h->rchild=t;
}
void out(node* h){
    if(h==NULL)return;
    out(h->lchild);
    out(h->rchild);
    cout << h->num << '\n';
}
int main(){
    int n;
    cin >> n;
    cin >> k;
    head=new node;
    head->num=k;
    head->lchild=head->rchild=NULL;
    for(int i=1;i<n;i++){
        cin >> k;
        push(k,head);
    }
    deep(1,head);
    cout << "deep=" << ans << '\n';
    out(head);
    return 0;
}