PRoblem Link：http://139.129.36.234/problem.php?id=1274

題目描述

輸入

輸出

樣例輸入

52 5 1 3 4
樣例輸出
-1 2 2 5 3 
提示
來源
北郵機試真題
AC code：
#include<iostream>#include<algorithm>#include<stdio.h>#include<map>#include<math.h>#include<string.h>#include<queue>#include<vector>#include<set>#define LL long long#define exp 1e-9#define MAXN 1000010using namespace std;typedef struct BTNode{	int data;	BTNode *lchild;	BTNode *rchild;}BTNode;void insertBT(BTNode *&bt,int x){	BTNode *pre,*p;	p=bt;	int dir=0;	if(p==NULL)	{		bt = (BTNode *)malloc(sizeof(BTNode));		bt->data=x;		bt->lchild=NULL;		bt->rchild=NULL;		printf("-1 ");	}	else	{		while(p!=NULL)		{			pre=p;			if(p->data>x)			{				p=p->lchild;			}			else			{				p=p->rchild;			}		}		p = (BTNode *)malloc(sizeof(BTNode));		p->data=x;		p->lchild=NULL;		p->rchild=NULL;		if(pre->data>x)		{			pre->lchild=p;		}		else		{			pre->rchild=p;		}		printf("%d ",pre->data);	}}int main(){//	freopen("D://in.txt","r",stdin);	int n,i,x;	scanf("%d",&n);	BTNode *bt=NULL;	for(i=1;i<=n;i++)	{		scanf("%d",&x);		insertBT(bt,x);	}	puts("");	return 0;}