import numpy as np import math if __name__ == '__main__': def rotate(matrix): n = len(matrix[0]) for i in range(math.ceil((n-1)/2)): for j in range(i,n-i-1): temp = matrix[i][j] matrix[i][j] = matrix[n-1-j][i] matrix[n-1-j][i] = matrix[n-1-i][n-1-j]…

python3--算法基础:二维数组转90度 [0, 1, 2, 3][0, 1, 2, 3][0, 1, 2, 3][0, 1, 2, 3] 二维数组转90度 [0, 0, 0, 0][1, 1, 1, 1][2, 2, 2, 2][3, 3, 3, 3] #!/usr/bin/env python # -*- coding:utf-8 -*- # 算法基础:二维数组转90度 a = [col for col in range(4)] print(a) print("-------------…

  问题: You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). Follow up: Could you do this in-place?   分析: 二维数组a[n][n]顺时针旋转90度,要解决这个问题,无疑,第一件事儿就是找规律. 当n=1时,不用动了. 当n=2时, 旋转之后变为 有: a[0][0] = a[1][0] a[1][0] =…

本篇主要介绍了对一个N*N的数组,如果进行90度的旋转 首先,定义一个一维数组很简单,如下: a = [i for i in range(10)] print(a) -----结果----- 0, 1, 2, 3, 4, 5, 6, 7, 8, 9] 此写法与下面的写法是相同的效果: a = [] for i in range(10): a.append(i) print(a) -----结果----- [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] 那么二维数组应该如何进行创建呢…

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: Integers in each row are sorted in ascending from left to right. Integers in each column are sorted in ascending from top to bottom.…

原文转载自「刘悦的技术博客」https://v3u.cn/a_id_168 现在很多互联网企业学聪明了,知道应聘者有目的性的刷Leetcode原题,用来应付算法题面试,所以开始对这些题进行"魔改",比如北京某电商平台的这道题: 有一个正方形的岛,使用二维方形矩阵表示,岛上有一个醉汉,每一步可以往上下左右四个方向之一移动一格,如果超出矩阵范围他就死了,假设每一步的方向都是随机的(因为他是醉的),请计算n步以后他还活着的概率. 例如:输入矩阵大小2*2,起点(0,0),随机走出一步 n =…

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: Integers in each row are sorted in ascending from left to right. Integers in each column are sorted in ascending from top to bottom.…

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: Integers in each row are sorted from left to right. The first integer of each row is greater than the last integer of the previous ro…

LeetCode:搜索二维矩阵[74] 题目描述 编写一个高效的算法来判断 m x n 矩阵中,是否存在一个目标值.该矩阵具有如下特性: 每行中的整数从左到右按升序排列. 每行的第一个整数大于前一行的最后一个整数. 示例 1: 输入: matrix = [ [1, 3, 5, 7], [10, 11, 16, 20], [23, 30, 34, 50] ] target = 3 输出: true 示例 2: 输入: matrix = [ [1, 3, 5, 7], [10, 11, 16, 20…

Leetcode之二分法专题-240. 搜索二维矩阵 II(Search a 2D Matrix II) 编写一个高效的算法来搜索 m x n 矩阵 matrix 中的一个目标值 target.该矩阵具有以下特性: 每行的元素从左到右升序排列. 每列的元素从上到下升序排列. 示例: 现有矩阵 matrix 如下: [ [1, 4, 7, 11, 15], [2, 5, 8, 12, 19], [3, 6, 9, 16, 22], [10, 13, 14, 17, 24], [18, 21, 23…