二叉树的创建，先序遍历，中序遍历，后序遍历-蒲公英云

二叉树的创建，先序遍历，中序遍历，后序遍历

桃扇骨 2022-08-19 02:11 280阅读 0赞

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#include<stdio.h>
#include<stdlib.h>
#define OK 1
#define ERROR 0
typedef char TElemType;
typedef struct BiTNode{
    TElemType data;
    struct BiTNode *lchild, *rchild;
}BiTNode, *BiTree;
void CreateBiTree(BiTree &T){
    TElemType ch;
    fflush(stdin);
    scanf("%c", &ch);
    fflush(stdin);
    if('#' == ch){
        T = NULL;
    }else{
        T = (BiTNode *)malloc(sizeof(BiTNode));
        T->data = ch;
        CreateBiTree(T->lchild);
        CreateBiTree(T->rchild);
    }
}
void FirstOrder(BiTree &T){
    if(T){
        printf("%c ",T->data);
        FirstOrder(T->lchild);
        FirstOrder(T->rchild);
    }
}
void InOrder(BiTree &T){
    if(T){
        InOrder(T->lchild);
        printf("%c ",T->data);
        InOrder(T->rchild);
    }
}
void LastOrder(BiTree &T){
    if(T){
        LastOrder(T->lchild);
        LastOrder(T->rchild);
        printf("%c ",T->data);
    }    
}
int main(){
    printf("*******************二叉树遍历*************************\n");
    printf("1、创建二叉树   2、先序遍历   3、中序遍历   4、后序遍历   5、退出\n");
    printf("请选择：\n");
    int n;
    scanf("%d", &n);
    while(1){
        switch(n){
            case 1:
                BiTree T;
                CreateBiTree(T);
                break;
            case 2:
                FirstOrder(T);
                printf("\n");
                break;
            case 3:
                InOrder(T);
                printf("\n");
                break;
            case 4:
                LastOrder(T);
                printf("\n");
                break;
            case 5:
                exit(1);
            default:
                printf("输入有误！，请重新输入\n");
                break;
        }
        printf("请选择：\n");
        scanf("%d", &n);
    }
    return 0;
}