6-9 二叉树的遍历

6-9 二叉树的遍历 (25分)

本题要求给定二叉树的4种遍历。

函数接口定义：

void InorderTraversal( BinTree BT );
void PreorderTraversal( BinTree BT );
void PostorderTraversal( BinTree BT );
void LevelorderTraversal( BinTree BT );

其中BinTree结构定义如下：

typedef struct TNode *Position;
typedef Position BinTree;
struct TNode{ElementType Data;BinTree Left;BinTree Right;
};

要求4个函数分别按照访问顺序打印出结点的内容，格式为一个空格跟着一个字符。

裁判测试程序样例：

#include <stdio.h>
#include <stdlib.h>typedef char ElementType;
typedef struct TNode *Position;
typedef Position BinTree;
struct TNode{ElementType Data;BinTree Left;BinTree Right;
};BinTree CreatBinTree(); /* 实现细节忽略 */
void InorderTraversal( BinTree BT );
void PreorderTraversal( BinTree BT );
void PostorderTraversal( BinTree BT );
void LevelorderTraversal( BinTree BT );int main()
{BinTree BT = CreatBinTree();printf("Inorder:");    InorderTraversal(BT);    printf("\n");printf("Preorder:");   PreorderTraversal(BT);   printf("\n");printf("Postorder:");  PostorderTraversal(BT);  printf("\n");printf("Levelorder:"); LevelorderTraversal(BT); printf("\n");return 0;
}
/* 你的代码将被嵌在这里 */

输出样例（对于图中给出的树）：

Inorder: D B E F A G H C I
Preorder: A B D F E C G H I
Postorder: D E F B H G I C A
Levelorder: A B C D F G I E H

代码实现(C语言)

#include <stdio.h>
#include <stdlib.h>typedef char ElementType;
typedef struct TNode *Position;
typedef Position BinTree;
struct TNode{ElementType Data;BinTree Left;BinTree Right;
};BinTree CreatBinTree(); /* 实现细节忽略 */
void InorderTraversal( BinTree BT );
void PreorderTraversal( BinTree BT );
void PostorderTraversal( BinTree BT );
void LevelorderTraversal( BinTree BT );int main()
{BinTree BT = CreatBinTree();printf("Inorder:");    InorderTraversal(BT);    printf("\n");printf("Preorder:");   PreorderTraversal(BT);   printf("\n");printf("Postorder:");  PostorderTraversal(BT);  printf("\n");printf("Levelorder:"); LevelorderTraversal(BT); printf("\n");return 0;
}
/* 你的代码将被嵌在这里 */
void InorderTraversal( BinTree BT )
{if(BT != NULL){InorderTraversal(BT->Left);printf(" %c", BT->Data);InorderTraversal(BT->Right);}}void PreorderTraversal( BinTree BT )
{if(BT != NULL){printf(" %c", BT->Data);PreorderTraversal(BT->Left);PreorderTraversal(BT->Right);}
}void PostorderTraversal( BinTree BT )
{if(BT != NULL){PostorderTraversal(BT->Left);PostorderTraversal(BT->Right);printf(" %c", BT->Data);  }  
}void LevelorderTraversal( BinTree BT )
{BinTree queue[100], temp;//queue为元素类型为BinTree的数组，当作队列使用，temp用来暂存当前节点int head=0,rear=0;//从队尾进队头出if(BT){queue[rear++] = BT;while(head-rear)//队非空时{temp = queue[head++];//当前节点为队头节点printf(" %c",temp->Data);if(temp->Left) queue[rear++] = temp->Left;if(temp->Right) queue[rear++] = temp->Right;}}
}

->Data);
if(temp->Left) queue[rear++] = temp->Left;
if(temp->Right) queue[rear++] = temp->Right;
}
}
}