二叉树层次建树.

#include <iostream>
#include <stdlib.h>

using namespace std;

struct BinTree
{
    int data;
    BinTree *Left,*Right;
};   

void del(BinTree *p)
{
    if(p->Left)
        del(p->Left);
    if(p->Right)
        del(p->Right);
    delete p;
}   
BinTree *Creat(int *node, int &size, int pos)
{
  
    if(pos>=size)
        return NULL;
    BinTree *t = new BinTree;
    t->data=node[pos];
    t->Left=Creat(node, size, pos*2+1);
    t->Right=Creat(node, size, pos*2+2);
    return t;
}

void DFS( BinTree*p)
{
    if(!p)return ;
    cout<<p->data<<" ";
    DFS(p->Left);
    DFS(p->Right);
}
    
int main(int argc, char *argv[])
{
    BinTree *tree;
    int node[]={/
                1,2,3,4,5,6,7,8,9,10,11,12,/
                13,45,15,16,17,18,19,20,21,/
                22,23,24,25,26,27,28,29,30,31
                };
    int size = sizeof(node) / sizeof(node[0]);
    tree=Creat(node, size, 0);
    DFS(tree);
    del(tree);
    system("PAUSE"); 
    return 0;
}
=====================================================================

引自:http://community.youkuaiyun.com/Expert/topic/3948/3948858.xml?temp=.7505304