此题要求实现给定二叉搜索树的5种常用操作。
1 #include <stdio.h> 2 #include <stdlib.h> 3 4 typedef int ElementType; 5 typedef struct TNode *Position; 6 typedef Position BinTree; 7 struct TNode{ 8 ElementType Data; 9 BinTree Left; 10 BinTree Right; 11 }; 12 13 void PreorderTraversal( BinTree BT ); /* 先序遍历，由裁判实现，细节不表 */ 14 void InorderTraversal( BinTree BT ); /* 中序遍历，由裁判实现，细节不表 */ 15 16 BinTree Insert( BinTree BST, ElementType X ); 17 BinTree Delete( BinTree BST, ElementType X ); 18 Position Find( BinTree BST, ElementType X ); 19 Position FindMin( BinTree BST ); 20 Position FindMax( BinTree BST ); 21 22 int main() 23 { 24 BinTree BST, MinP, MaxP, Tmp; 25 ElementType X; 26 int N, i; 27 28 BST = NULL; 29 scanf("%d", &N); 30 for ( i=0; i<N; i++ ) { 31 scanf("%d", &X); 32 BST = Insert(BST, X); 33 } 34 printf("Preorder:"); PreorderTraversal(BST); printf(" "); 35 MinP = FindMin(BST); 36 MaxP = FindMax(BST); 37 scanf("%d", &N); 38 for( i=0; i<N; i++ ) { 39 scanf("%d", &X); 40 Tmp = Find(BST, X); 41 if (Tmp == NULL) printf("%d is not found ", X); 42 else { 43 printf("%d is found ", Tmp->Data); 44 if (Tmp==MinP) printf("%d is the smallest key ", Tmp->Data); 45 if (Tmp==MaxP) printf("%d is the largest key ", Tmp->Data); 46 } 47 } 48 scanf("%d", &N); 49 for( i=0; i<N; i++ ) { 50 scanf("%d", &X); 51 BST = Delete(BST, X); 52 } 53 printf("Inorder:"); InorderTraversal(BST); printf(" "); 54 55 return 0; 56 } 57 /* 你的代码将被嵌在这里 */ 58 BinTree Insert( BinTree BST, ElementType X ) 59 { 60 if ( !BST ) { 61 BST = (BinTree)malloc(sizeof(struct TNode)); 62 BST->Left = BST->Right = NULL; 63 BST->Data = X; 64 } 65 else { 66 if ( X < BST->Data ) 67 BST->Left = Insert(BST->Left, X); // 递归插入左子树 68 else if ( X > BST->Data ) 69 BST->Right = Insert(BST->Right, X); // 递归插入右子树 70 /* else X 已经存在，什么也不做 */ 71 } 72 73 return BST; 74 } 75 76 BinTree Delete( BinTree BST, ElementType X ) 77 { 78 BinTree Tmp; 79 80 if ( !BST ) printf("Not Found "); // 要删除元素未找到 81 else { 82 if ( X < BST->Data ) 83 BST->Left = Delete(BST->Left, X); // 从左子树递归删除 84 else if ( X > BST->Data ) 85 BST->Right = Delete(BST->Right, X);// 从右子树递归删除 86 else { // BST 就是要删除的节点 87 // 被删除节点有左右两个子节点 88 if ( BST->Left && BST->Right ) { 89 // 从右子树中找到最小元素填充被删除节点 90 Tmp = FindMin(BST->Right); 91 BST->Data = Tmp->Data; 92 // 删除 右子树中的最小元素 93 BST->Right = Delete(BST->Right, BST->Data); 94 } 95 else { // 被删除节点有一个或无子节点 96 Tmp = BST; 97 if ( !BST->Left ) // 只有右节点或无子节点 98 BST = BST->Right; 99 else // 只有左孩子 100 BST = BST->Left; 101 free(Tmp); 102 } 103 } 104 } 105 106 return BST; 107 } 108 109 Position Find( BinTree BST, ElementType X ) 110 { 111 if ( !BST ) return NULL; // 没找着，返回空指针 112 if ( X < BST->Data ) 113 return Find(BST->Left, X); 114 else if ( X > BST->Data ) 115 return Find(BST->Right, X); 116 else 117 return BST; 118 } 119 120 Position FindMin( BinTree BST ) 121 { 122 if ( !BST ) return NULL; 123 else if ( !BST->Left ) 124 return BST; 125 else 126 return FindMin(BST->Left); 127 } 128 129 Position FindMax( BinTree BST ) 130 { 131 if ( BST ) 132 while ( BST->Right ) BST = BST->Right; 133 return BST; 134 }