leetcode 48. Rotate Image
来源:互联网 发布:马云淘宝初期如何推广 编辑:程序博客网 时间:2024/06/08 11:54
Discription
You are given an n x n 2D matrix representing an image.
Rotate the image by 90 degrees (clockwise).
Note:
You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.
Example 1:
Given input matrix =
[
[1,2,3],
[4,5,6],
[7,8,9]
],
rotate the input matrix in-place such that it becomes:
[
[7,4,1],
[8,5,2],
[9,6,3]
]
Example 2:
Given input matrix =
[
[ 5, 1, 9,11],
[ 2, 4, 8,10],
[13, 3, 6, 7],
[15,14,12,16]
],
rotate the input matrix in-place such that it becomes:
[
[15,13, 2, 5],
[14, 3, 4, 1],
[12, 6, 8, 9],
[16, 7,10,11]
]
思路
模拟题,找规律即可。要注意循环边界,避免重复。
时间复杂度:
空间复杂度:
代码
class Solution {public: // matrix[i][j] -> matrix[j][n - 1 - i] // matrix[j][n - 1 - i] -> matrix[n - 1 - i][n - 1 - j] // matrix[n - 1 - i][n - 1 - j] -> matrix[n - 1 - j][n - 1 - (n - 1 - i)] // matrix[n - 1 - j][n - 1 - (n - 1 - i))] -> matrix[i][j] void rotate(vector<vector<int>>& matrix) { int n = matrix.size(); for (int i = 0; i < (n + 1) / 2; i++) { for (int j = 0; j < n / 2; j++) { int temp4 = matrix[j][n - 1 - i]; matrix[j][n - 1 - i] = matrix[i][j]; int temp16 = matrix[n - 1 - i][n - 1 - j]; matrix[n - 1 - i][n - 1 - j] = temp4; int temp13 = matrix[n - 1 - j][n - 1 - (n - 1 - i)]; matrix[n - 1 - j][n - 1 - (n - 1 - i)] = temp16; matrix[i][j] = temp13; } } }};
阅读全文
0 0
- [LeetCode]48.Rotate Image
- LeetCode 48. Rotate Image
- LeetCode 48.Rotate Image
- LeetCode --- 48. Rotate Image
- [Leetcode] 48. Rotate Image
- [leetcode] 48. Rotate Image
- Leetcode 48. Rotate Image
- 48. Rotate Image LeetCode
- [LeetCode]48. Rotate Image
- leetcode 48. Rotate Image
- Leetcode 48. Rotate Image
- LeetCode 48. Rotate Image
- LeetCode *** 48. Rotate Image
- [LeetCode]48. Rotate Image
- LeetCode 48. Rotate Image
- LeetCode-48.Rotate Image
- [LeetCode] 48. Rotate Image
- LeetCode 48. Rotate Image
- web项目容器化笔记
- 【机器学习】基础术语
- Android O源码阅读之 DocumentsUI和Unknown source Apk安装
- Java学习笔记之IO(十五):PrintStream打印流
- 【面试】线程/线程池总结
- leetcode 48. Rotate Image
- 第七周 项目2
- (08)oracle新人笔记------数据的相关操作
- 安装包测试之快照工具Total Uninstall
- Java解析xml文件,获得相应的值
- ros入门之用catkin和rosmake创建和编译功能包
- python高阶函数:map(f,[list]),reduce(f,[list],可选初始值),
- aliyun阿里云Maven仓库地址——加速你的maven构建
- 找到一个讲的很详细的js的原型闭包的教程