题目地址：HDU 1710
已知二叉树先序和中序求后序。
#include <stdio.h>
#include <string.h>
int a[1001], cnt;
typedef struct node
{
int date ;
node *lchild , *rchild ;
}*tree;
int getk(int ch,int ino[],int is,int n)
{
for(int i = is ; i <= is + n -1 ; i++)
if(ino[i]==ch)return i;
}
void gettree(tree &t,int pre[],int ino[],int ps,int is,int n)
{
if(n==0) t = NULL;
else
{
t = new node;
t->date = pre[ps];
int k = getk(pre[ps],ino,is,n);
if(k == is) t->lchild = NULL;
else
gettree(t->lchild,pre,ino,ps+1,is,k-is);
if(k == is+n-1) t->rchild = NULL;
else
gettree(t->rchild,pre,ino,ps+1+(k-is),k+1,n-1-(k-is));
}
}
void pritree1(tree t)
{
if(t)
{
pritree1(t->lchild);
pritree1(t->rchild);
a[cnt++]=t->date;
}
}
int main()
{
int i, n, t;
int pre[1001] , ino[1001] ;
while(scanf("%d", &n)!=EOF)
{
cnt=0;
tree head;
for(i=0; i<n; i++)
{
scanf("%d",&pre[i]);
}
for(i=0; i<n; i++)
{
scanf("%d",&ino[i]);
}
gettree(head,pre,ino,0,0,n);
pritree1(head);
for(i=0; i<cnt-1; i++)
printf("%d ",a[i]);
printf("%d\n",a[cnt-1]);
}
return 0;
}
HDU 1710 Binary Tree Traversals(二叉树）,布布扣,bubuko.com
HDU 1710 Binary Tree Traversals(二叉树）
原文地址：http://blog.csdn.net/scf0920/article/details/38313789
