/* * 74.Search in a 2D Matrix * 12.5 by Mingyang * 这里面的对应挺巧的: * 这个就是将2D矩阵转化成1行数组的对应表.所以对于二分查找法的初始值为: * low=0,high=rows*columns-1(总共数值的个数,因为从0开始所以减1). * 为了能够方便在given 2D matrix找到需要比对的值 * 我们还是需要确定行数和列数,通过上表可以看出,行数是position/columns,而列数是position%columns,…

/* * 240.Search in a 2D Matrix II * 2016-6-17by Mingyang * From left-bottom to right-top * 他这道题目虽说是用了BS,但是并不一定要有mid,这里就从最左下角到右上角 * 这个数大于同一列的,小于同一行的,只要跟target比较以后,就可以要么删除一列,要么删除一行--------找拐点 * 这个题目自己做的时候给出了一个nlog的方案,先是row从下往上走,在同一row里面再继续bs * 但是这个题目的好…

二分查找 1.二分查找的时间复杂度分析: 二分查找每次排除掉一半不合适的值,所以对于n个元素的情况来说: 一次二分剩下:n/2 两次:n/4 m次:n/(2^m) 最坏情况是排除到最后一个值之后得到结果,所以:n/(2^m) = 1 2^m = n 所以时间复杂度为:log2(n) 2.二分查找的实现方法: (1)递归 int RecursiveBinSearch(int arr[], int bottom, int top, int key) { if (bottom <= top) { in…

74. Search a 2D Matrix 整个二维数组是有序排列的,可以把这个想象成一个有序的一维数组,然后用二分找中间值就好了. 这个时候需要将全部的长度转换为相应的坐标,/col获得x坐标,%col获得y坐标 class Solution { public: bool searchMatrix(vector<vector<int>>& matrix, int target) { int row = matrix.size(); ) return false; ].s…

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…

74. 搜索二维矩阵 74. Search a 2D Matrix 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. LeetCode74. Search a 2D Matrix中等 示例 1: 输入: matrix = [   [1, 3, 5, 7],   [10, 11, 16, 20],   [23, 30, 34, 50]] target = 3 输出: tru…

题目: 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 previou…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 左下或者右上开始查找 顺序查找 库函数 日期 题目地址:https://leetcode.com/problems/search-a-2d-matrix/description/ 题目描述 Write an efficient algorithm that searches for a value in an m x n matrix. This m…

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…

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…