poj2255——先序中序求后序

之前写过一个数字的稍作修改便可以AC，对于题目要求以文本结束则结束程序需要输入不为EOF即可。

#include<stdio.h>
#include<string.h>
typedef struct btnode{
    char data;
    struct btnode *left;
    struct btnode *right;
}treenode;
treenode *gettree(int prel,int prer,int inl,int inr,char preorder[],char inorder[]){
    if(prel>prer)
        return NULL;
    treenode *root;     
    root=new treenode;
    root->data=preorder[prel];
    if(prel==prer){
        root->left=NULL;
        root->right=NULL;
        return root;
    }
    int temp;
    for(int i=1;i<=inr;i++)
        if(inorder[i]==preorder[prel]){
            temp=i;
            break;
        }
    root->left=gettree(prel+1,prel+(temp-inl),inl,temp-1,preorder,inorder);
    root->right=gettree(prel+(temp-inl)+1,prer,temp+1,inr,preorder,inorder);
    return root;
}
void postorder(treenode *t){
    if(t!=NULL){
        postorder(t->left);
        postorder(t->right);
        printf("%c",t->data);
    }
}
int main(){
    char preorder[101];
	char inorder[101];	
	while(scanf("%s%s",preorder,inorder)!=EOF){
    	int n=strlen(preorder);
		treenode *tree=gettree(0,n-1,0,n-1,preorder,inorder);
    	postorder(tree);
    	printf("
");
    }
    return 0;
}