hdu 1710 Binary Tree Traversals

/* *********************************************** Author :xryz Email :[email protected] Created Time :4-22 11:41:40 File Name :BinaryTreeTraversals.cpp ************************************************ */

#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
using namespace std;

typedef struct node *tree;
typedef struct node
{
    int data;
    tree left;
    tree right;
};

bool flag;
tree root;
int pro[1024],in[1024];

tree gettree(int *a,int *b,int n)//递归建树
{
    tree t;
    int i;
    for(i=0;i<n;i++)
    {
        if(a[0]==b[i])
        {
            t=(tree)malloc(sizeof(struct node));
            t->data=b[i];
            t->left=gettree(a+1,b,i);
            t->right=gettree(a+1+i,b+1+i,n-i-1);
            return t;
        }
    }
    return NULL;
}

void postorder(tree p)//后序遍历
{
    if(p!=NULL)
    {
        postorder(p->left);
        postorder(p->right);
        if(flag) printf(" ");
        else flag++;
        printf("%d",p->data);
    }
}

int main()
{
    int i,n;
    while(~scanf("%d",&n))
    {
        for(i=0;i<n;i++)
            scanf("%d",&pro[i]);
        for(i=0;i<n;i++)
            scanf("%d",&in[i]);
        root=gettree(pro,in,n);
        flag=0;
        postorder(root);
        printf("\n");
    }
    return 0;
}