我是想實(shí)現(xiàn)創(chuàng)建二叉樹(shù)的，用前序式。但是我在子函數(shù)createtree中調(diào)用malloc分配內(nèi)存，創(chuàng)建成功后回到主函數(shù)，分配的內(nèi)存空間沒(méi)有了。我在單步調(diào)試時(shí)創(chuàng)建時(shí)可以看見(jiàn)head的地址的，但函數(shù)返回main函數(shù)時(shí)地址就變回void*的了，不是malloc子函數(shù)分配的內(nèi)存在進(jìn)程結(jié)束前不會(huì)自動(dòng)free的嗎？#include<stdio.h>#include<stdlib.h>typedef struct _tree{char data;struct _tree *lchild;struct _tree *rchild;}bittree;int createtree(bittree *head){char data;fscanf(stdin,"%c",&data);getchar();if('#' != data){head = (bittree*)malloc(sizeof(bittree));if(head == NULL) exit(0);head->data = data;head->lchild = NULL;head->rchild = NULL;createtree(head->lchild);createtree(head->rchild);}return 1;}int main(){bittree *head = NULL;createtree(head);printf("root lchild data = %c\n",head->lchild->data);return 1;}