按照給定的關鍵字集合,建立二叉排序樹。在建立的二叉排序樹上查找指定的關鍵字,查找成功,輸出找到該關鍵字比較的次數;查找不成功,輸出-1.
輸入
關鍵字個數n;
關鍵字集合;
要查找的關鍵字;
輸出
查找成功輸出比較的次數,否則輸出-1。
樣例輸入
12
25 18 46 2 53 39 32 4 74 67 60 11
74
樣例輸出
4
#include<iostream>
#include<stdio.h>
#include<string>
using namespace std;
int flag;
struct btree
{
int date;
btree *left, *right;
};
void creathead(btree *&root)
{
root = new btree;
cin >> root->date;
root->left = root->right = NULL;
}
void creatbtree(btree *& root, int insert)
{
if (root == NULL)
{
root = new btree;
root->date = insert;
root->left = root->right = NULL;
return;
}
if (root->date < insert)
{
creatbtree(root->right, insert);
}
else if (root->date>insert)
{
creatbtree(root->left, insert);
}
}
void find(btree *root, int tar, int cnt)
{
if (root == NULL)
{
return;
}
if (tar == root->date)
{
cout << cnt + 1;
flag = 1;
return;
}
else if (tar < root->date)
{
find(root->left, tar, cnt + 1);
}
else if (tar > root->date)
{
find(root->right, tar, cnt + 1);
}
}
int main()
{
int n;
cin >> n;
btree *root;
int k;
flag = 0;
int num;
creathead(root);
for (int i = 2; i <= n; i++)
{
cin >> num;
creatbtree(root, num);
}
cin >> k;
find(root, k, 0);
if (!flag)
cout << "-1";
return 0;
}