SDUT-2136 数据结构实验之二叉树的建立与遍历

#include<stdio.h>
#include<stdlib.h>
struct Tree{
     char data;
     struct Tree *lchild, *rchild;
}*t;
int cnt=0;//用于统计叶子的数目
struct Tree *creat(struct Tree *t)//根据先序建立二叉树
{
     char ch;
     ch = getchar();
     if(ch==‘,‘)
            t = NULL;
     else
     {
          t = (struct Tree *)malloc(sizeof(struct Tree));
          t->data = ch;
          t->lchild= creat(t->lchild);
          t->rchild= creat(t->rchild);
     }
     return t;
}
void Inorder(struct Tree *t)//中序遍历
{
    if(t!=NULL)
    {
         Inorder(t->lchild);
         printf("%c", t->data);
         Inorder(t->rchild);
    }
}
void Postorder(struct Tree *t)//后续遍历
{
    if(t!=NULL)
    {
        Postorder(t->lchild);
        Postorder(t->rchild);
        printf("%c", t->data);
    }
}
void leaf(struct Tree *t)//求叶子节点数目
{
    if(t)
    {
        if((t->lchild==NULL) && (t->rchild==NULL))
            cnt++;
         leaf(t->lchild);
         leaf(t->rchild);
    }
}

int deep(struct Tree *t)// 求二叉树深度
{
    int l, r;
    if(!t)
        return 0;
    l = deep(t->lchild);
    r = deep(t->rchild);
    return l>r?l+1:r+1;
}
int main()
{
     struct Tree *root;
     root = creat(root);
     Inorder(root);
     printf("\n");
     Postorder(root);
     printf("\n");
     leaf(root);
     printf("%d\n", cnt);
     printf("%d\n", deep(root));

     return 0;
}