题目
解决
思路
正常建立一棵AVL树
实现
Code1
#include<cstdio>
#include<algorithm>
using namespace std;
const int maxn = 25;
struct node{
int data;
int height;
node* lchild;
node* rchild;
};
node* newNode(int x){
node* Node = new node;
Node->data = x;
Node->height = 1;
Node->lchild = Node->rchild = NULL;
return Node;
}
int getHeight(node* root){
if(root == NULL) return 0;
return root->height;
}
void updateHeight(node* root){
root->height = max(getHeight(root->lchild), getHeight(root->rchild)) + 1;
}
void L(node* &root){
node* temp = root->rchild;
root->rchild = temp->lchild;
temp->lchild = root;
updateHeight(root);
updateHeight(temp);
root = temp;
}
void R(node* &root){
node* temp = root->lchild;
root->lchild = temp->rchild;
temp->rchild = root;
updateHeight(root);
updateHeight(temp);
root = temp;
}
int getBalanceFactor(node* root){
return getHeight(root->lchild) - getHeight(root->rchild);
}
void insert(node* &root, int x){
if(root == NULL){
root = newNode(x);
return;
}
if(x < root->data){
insert(root->lchild, x);
updateHeight(root);
if(getBalanceFactor(root) == 2){
if(getBalanceFactor(root->lchild) == 1){ //LL
R(root);
}else if(getBalanceFactor(root->lchild) == -1){ //LR
L(root->lchild);
R(root);
}
}
}else{
insert(root->rchild, x);
updateHeight(root);
if(getBalanceFactor(root) == -2){
if(getBalanceFactor(root->rchild) == -1){ //RR
L(root);
}else if(getBalanceFactor(root->rchild) == 1){ //RL
R(root->rchild);
L(root);
}
}
}
}
node* create(int data[], int n){
node* root = NULL;
for(int i=0; i<n; i++){
insert(root, data[i]);
}
return root;
}
int main(){
int n;
scanf("%d", &n);
int data[maxn];
for(int i=0; i<n; i++){
scanf("%d", &data[i]);
}
node* root = create(data, n);
printf("%d", root->data);
return 0;
}
