二叉树的创建，先序遍历，中序遍历，后序遍历

桃扇骨 2022-08-19 02:11 161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;
    }

[Center]: /images/20220731/7a540eeb14da4c458ba5c8d0c35b63ba.png
[Center 1]: /images/20220731/63d6c93c7816467a8cef98ab565d89ac.png