来学算法 #9 AVL树 （2） ： 实现

在实现34重构后，我们只需要实现插入和删除数据的函数就可以完成AVL树的实现了，AVL的重构核心已经给出了，不再赘述。直接放上完成的代码。

#include <bits/stdc++.h>

typedef struct node {
    int data;
    struct node *father;
    struct node *lch;
    struct node *rch;
} Node, *ptrNode;

int height(ptrNode ptr) {
    int lch, rch;
    if (ptr == NULL) {
        return -1;
    }
    if (ptr->lch == NULL && ptr->rch == NULL) {
        return 0;
    }
    lch = height(ptr->lch);
    rch = height(ptr->rch);
    return (lch > rch ? lch : rch) + 1;
}

bool isbalanced(ptrNode ptr) {
    int hleft, hright;
    if (ptr == NULL) {
        return true;
    }
    hleft = height(ptr->lch);
    hright = height(ptr->rch);
    if (abs(hleft - hright) < 2) {
        return true;
    }
    return false;
}

void preorder(ptrNode root) {
    if (root == NULL)
        return;
    printf("%d ", root->data);
    preorder(root->lch);
    preorder(root->rch);
}

ptrNode create(int data) {
    ptrNode temp = new Node;
    temp->data = data;
    temp->lch = NULL;
    temp->rch = NULL;
    temp->father = NULL;
    return temp;
}

ptrNode rerotate(ptrNode a, ptrNode b, ptrNode c, ptrNode T1, ptrNode T2,
                 ptrNode T3, ptrNode T4) {
    //调整内部关系，完成34重构
    if (T1)
        T1->father = a;
    a->lch = T1;
    if (T2)
        T2->father = a;
    a->rch = T2;
    if (T3)
        T3->father = c;
    c->lch = T3;
    if (T4)
        T4->father = c;
    c->rch = T4;
    a->father = b, b->lch = a;
    c->father = b, b->rch = c;
    return b;
}

ptrNode operate_to_balance(ptrNode &a, ptrNode a_father) {
    // a_father为这一个子树的父结点，方便连接
    ptrNode b = (height(a->lch) >= height(a->rch)) ? (a->lch) : (a->rch);
    ptrNode c = (height(b->lch) >= height(b->rch)) ? (b->lch) : (b->rch);
    ptrNode father_control;
    if (a->lch == b && b->lch == c) { // left left
        father_control = rerotate(c, b, a, c->lch, c->rch, b->rch, a->rch);
    }
    if (a->lch == b && b->rch == c) { // left right
        father_control = rerotate(b, c, a, b->lch, c->lch, c->rch, a->rch);
    }
    if (a->rch == b && b->lch == c) { // right left
        father_control = rerotate(a, c, b, a->lch, c->lch, c->rch, b->rch);
    }
    if (a->rch == b && b->rch == c) { // right right
        father_control = rerotate(a, b, c, a->lch, b->lch, c->lch, c->rch);
    }
    father_control->father = a_father;
    return father_control;
}

ptrNode find(ptrNode ptr, int data) {
    ptrNode temp = NULL;
    if (ptr->data == data) {
        return ptr;
    }

    if (ptr->data > data) {
        if (ptr->lch != NULL) {
            temp = find(ptr->lch, data);
        }
    } else {
        if (ptr->rch != NULL) {
            temp = find(ptr->rch, data);
        }
    }
    return temp;
}

ptrNode addnode(ptrNode ptr, int data, ptrNode root) {
    if (data < ptr->data) {
        if (ptr->lch == NULL) {
            ptr->lch = create(data);
            ptr->lch->father = ptr;
            for (ptrNode _rebal = ptr; _rebal; _rebal = _rebal->father) {
                if (!isbalanced(_rebal)) {
                    if (_rebal->father == NULL) {
                        root = operate_to_balance(_rebal, NULL);
                        root->father = NULL;
                        return root;
                    }
                    if (_rebal->father->lch == _rebal) {
                        _rebal->father->lch =
                            operate_to_balance(_rebal, _rebal->father);
                    } else {
                        _rebal->father->rch =
                            operate_to_balance(_rebal, _rebal->father);
                    }
                    while (_rebal->father != NULL) {
                        _rebal = _rebal->father;
                    }
                    root = _rebal;
                    break;
                }
            }
        } else {
            root = addnode(ptr->lch, data, root);
        }
    } else {
        if (ptr->rch == NULL) {
            ptr->rch = create(data);
            ptr->rch->father = ptr;
            for (ptrNode _rebal = ptr; _rebal; _rebal = _rebal->father) {
                if (!isbalanced(_rebal)) {
                    if (_rebal->father == NULL) {
                        root = operate_to_balance(_rebal, NULL);
                        root->father = NULL;
                        return root;
                    }
                    if (_rebal->father->lch == _rebal) {
                        _rebal->father->lch =
                            operate_to_balance(_rebal, _rebal->father);
                    } else {
                        _rebal->father->rch =
                            operate_to_balance(_rebal, _rebal->father);
                    }
                    while (_rebal->father != NULL) {
                        _rebal = _rebal->father;
                    }
                    root = _rebal;
                    break;
                }
            }
        } else {
            root = addnode(ptr->rch, data, root);
        }
    }
    return root;
}

ptrNode deletedata(ptrNode ptr, int data) {
    ptrNode _delete = find(ptr, data);
    ptrNode _rebal;
    if (_delete->lch == NULL && _delete->rch == NULL) { //_delete是叶节点
        if (_delete->father == NULL) {
            delete _delete;
            _delete = NULL;
            return NULL;
        }
        if (_delete->father->lch == _delete) {
            _delete->father->lch = NULL;
        } else {
            _delete->father->rch = NULL;
        }
    } else if (_delete->lch != NULL && _delete->rch == NULL) {
        if (_delete->father == NULL) {
            _delete->lch->father = NULL;
            ptrNode root = _delete->lch;
            delete _delete;
            _delete = NULL;
            return root;
        } else {
            if (_delete->father->lch == _delete) {
                _delete->father->lch = _delete->lch;
                _delete->lch->father = _delete->father;
            } else {
                _delete->father->rch = _delete->lch;
                _delete->lch->father = _delete->father;
            }
        }
    } else if (_delete->lch == NULL && _delete->rch != NULL) {
        if (_delete->father == NULL) {
            _delete->rch->father = NULL;
            ptrNode root = _delete->rch;
            delete _delete;
            _delete = NULL;
            return root;
        } else {
            if (_delete->father->lch == _delete) {
                _delete->father->lch = _delete->rch;
                _delete->rch->father = _delete->father;
            } else {
                _delete->father->rch = _delete->rch;
                _delete->rch->father = _delete->father;
            }
        }
    } else if (_delete->lch != NULL && _delete->rch != NULL) {
        ptrNode replace = _delete->rch;
        ptrNode root;
        while (replace->lch) {
            replace = replace->lch;
        }
        _delete->data = replace->data;
        root = deletedata(_delete->rch, replace->data);
        return root;
    }

    _rebal = _delete->father;
    delete _delete;
    _delete = NULL;

    ptrNode root;
    while (_rebal) {
        if (!isbalanced(_rebal)) {
            if (_rebal->father == NULL) {
                root = operate_to_balance(_rebal, NULL);
                root->father = NULL;
                return root;
            }
            if (_rebal->father->lch == _rebal) {
                _rebal->father->lch =
                    operate_to_balance(_rebal, _rebal->father);
            } else {
                _rebal->father->rch =
                    operate_to_balance(_rebal, _rebal->father);
            }
        }
        if (_rebal->father == NULL) {
            root = _rebal;
        }
        _rebal = _rebal->father;
    }
    return root;
}

int main() {
    ptrNode tree, temp;
    int data;

    //以下是creat和addnode模块
    scanf("%d", &data);
    tree = create(data);
    while (1) {
        scanf("%d", &data);
        if (data == 0)
            break;
        tree = addnode(tree, data, tree);
    }
    tree = deletedata(tree, 4);
    printf("the height of this tree : %d\n", height(tree) + 1);
    return 0;
}

标签：来学,father,AVL,算法,rch,rebal,NULL,lch,delete
来源： https://blog.csdn.net/fushanzhifeng/article/details/113796971