【牛客網-名企高頻面試題】 NC72 二叉樹的映象
阿新 • • 發佈:2021-01-14
技術標籤:# 牛客網
題目描述:
操作給定的二叉樹,將其變換為源二叉樹的映象。
遞迴版本:
public void Mirror_1(TreeNode root) {
if(root == null){
return;
}
TreeNode temp = root.left;
root.left = root.right;
root.right = temp;
Mirror(root.left);
Mirror (root.right);
}
非遞迴版本:
/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val) {
this.val = val;
}
}
*/
import java.util.*;
public class Solution {
//利用二叉樹的廣度優先搜尋實現映象
public void Mirror(TreeNode root) {
if(root == null)
return;
Queue<TreeNode> nodes = new LinkedList<>();
TreeNode curr,temp;
nodes.offer(root);
while(!nodes.isEmpty()){
int len = nodes.size();
for(int i= 0;i< len;i++){
curr = nodes. poll();
temp = curr.left;
curr.left = curr.right;
curr.right = temp;
if(curr.left != null)
nodes.offer(curr.left);
if(curr.right != null)
nodes.offer(curr.right);
}
}
}
}