数据结构 --- 二叉排序树的基本操作

二叉排序树的结构体

struct data{
    int sum;
    struct data *left ,*right;
};

---

二叉排序树的插入

void intree(struct data **tree,int a){   //二叉排序树的插入(非递归）
    struct data *tail = *tree;
    struct data *news = (struct data *)malloc(sizeof(struct data));
    news->sum = a;
    news->left = news->right = NULL;
    if(tail == NULL){
        (tail) = news;
    }
    while((tail) != NULL) {
        if ((tail)->sum > a) {
            if ((tail)->left == NULL) {
                (tail)->left = news;
                break;
            } else {
                tail= tail->left;
            }

        }else if(tail->sum < a) {
            if (tail->right == NULL) {
                tail->right = news;
                break;
            } else {
                tail= tail->right;
            }
        }

        if(tail->sum == a){    //当树内已经存在插入的数据时  不进行操作
            break;
        }
    }
}

 

---

二叉排序树找最小值

struct data *FindMin( struct data*  BST ){
    if(BST == NULL) return NULL;
    else if(BST->left == NULL)  return BST;
    else return FindMin(BST->left);
}

 

---

二叉排序树的删除 

struct data* Delete( struct data* BST, int X ){
    struct data* temp;
    if(BST == NULL ) {
         return NULL;
    }
    else{
        if(BST->sum > X){
            BST->left = Delete(BST->left,X);
        }else if(BST->sum < X){
            BST->right = Delete(BST->right,X);
        }
        else if(BST->sum == X){
            if(BST->left && BST->right){
                temp = FindMin(BST->right);
                BST->sum = temp->sum;
                BST->right = Delete(BST->right,BST->sum);
            }
            else{
                temp = BST;
                if(!BST->left ){
                    BST = BST->right;
                }
                else {
                    BST = BST->left;
                }
                free(temp);
            }
        }
        return BST;
    }
}

---

二叉排序树查找父结点

 

struct data * find_father(struct data *tree, int x){    // 线索二叉树寻找结点的父亲结点  中序遍历
   struct data *p = NULL;  //指向查找结点的前一个
    if(tree == NULL) return NULL;
    if(tree) {
        while (tree) {
            if (tree->sum == x) break;   //查到的出口
            if (tree->sum > x) {
                p = tree;
                tree = tree->left;
            } else if (tree->sum < x) {
                p = tree;
                tree = tree->right;
            } else {
                break;
            }
        }
    }
    return p;
}

---

二叉排序树的镜像 

/*
struct data * mirror_tree(struct data *tree){   //二叉树的镜像调换 （带返回值）
    if(tree == NULL) return NULL;
    if(tree){
        if(!tree->right && !tree->left) return NULL;  //左右子树都为空的情况下，直接返回空
        struct data *temp;   //临时储存左右子树的结点
        temp = tree->right;
        tree->right = tree->left;
        tree->left = temp;
        mirror_tree(tree->left);  //继续将左右子树结点下面的子树进行镜像调换
        mirror_tree(tree->right);
    }
    return tree;
}
*/


void mirror_tree(struct data* *tree) {  //不带返回值，传地址 镜像二叉树
    if ((*tree) == NULL) return;
    if (*tree) {
        if (!(*tree)->left && !(*tree)->right) return;
        struct data *temp = (*tree)->right;
        (*tree)->right = (*tree)->left;
        (*tree)->left = temp;
        mirror_tree(&(*tree)->left);
        mirror_tree(&(*tree)->right);
    }
}

---

统计二叉排序树内结点数 

int count_tree(struct data *tree){   //统计二叉树内的结点数
    if(tree == NULL) return 0;
    else return count_tree(tree->right) + count_tree(tree->left) + 1; //否则结点个数为左子树的结点个数+右子树的结点个数+1
}