二叉树遍历

/*字符串常用函数1、strlen(char const *string)2.strcpy(char *dst, char const *src )3,strcat(char *dst, char const *src)4,strcmp(char const *s1 , char const *s2)5,strncpy(char * dst, char const *src , int n)6,strncat(char *dst, char const *src, int n)7,strncmp(char const *s1 , char const *s2,int n)8,strchr(char * src , char c) //字符c第一次出现的位置9,strrchr(char *src, char c)//字符c最后一次出现的位置10，strpbrk(char const *str, char const *group)//查找字符串中任何一个字符第一次出现的位置11，strstr(char const *s1, char const *s2)//在s1中查找子串s212,strtok(char const *src, char const *token)//分解字符串为一组字符串。s为要分解的字符串，delim为分隔符字符串。首次调用时，s指向要分解的字符串，之后再次调用要把s设成NULL。*/#include<stdio.h>struct node{int num;struct node *lc;struct node *rc;} node;void preorder(struct node * root){if(root==NULL) return ;printf("%d ",root->num);preorder(root->lc);preorder(root->rc);}void middleorder(struct node * root){if(root==NULL) return ;middleorder(root->lc);printf("%d ",root->num);middleorder(root->rc);}// 元素查找int search(struct node * root, int x){//if(root==NULL) return  ;if(root->num==x) return x;else if(root->lc !=null)return search(root->lc,x);else if(root ->rc!=null)return search(root->rc,x);}//求深度int high(struct node * root,int h){int lh,rh,hif(root==null)  h=0 ;else{lh=high(root->lc);rh=high(root->rc);h=(lh>rh?lh:sh)+1;}return h;}