leetcode - 226. 翻转二叉树

题目

代码

#include <iostream>
#include <vector>
#include <queue>
using namespace std;

typedef struct TreeNode{
	int val;
	struct TreeNode *left, *right;
}TreeNode, *BiTree;

void create(BiTree &root){
	int tn;
	cin>>tn;
	if(tn == -1){
		root = NULL;
		return;
	}
	root = new TreeNode;
	root->val = tn;
	create(root->left);
	create(root->right);
}

// 递归
TreeNode* invertTree1(TreeNode* root) {
	if(!root){
		return NULL;
	}
	TreeNode *left = invertTree(root->left);
	TreeNode *right = invertTree(root->right);
	root->left = right;
	root->right = left;
	return root;
}

// 广度优先搜素 
TreeNode* invertTree(TreeNode* root) {
	if(!root){
		return root;
	}
	queue<TreeNode*> qn;
	qn.push(root);
	while(!qn.empty()){
		int qs = qn.size();
		for(int i = 0; i < qs; i++){
			TreeNode *p = qn.front();
			qn.pop();
			if(p->left || p->right){
				TreeNode *q = p->right;
				p->right = p->left;
				p->left = q;
			}
			if(p->left){
				qn.push(p->left);
			}
			if(p->right){
				qn.push(p->right);
			}
		}
	}
	return root;
}

int main(){
	TreeNode *root, *res;
	create(root);
	res = invertTree(root);
	return 0;
}