240. Search a 2D Matrix II
来源:互联网 发布:java开源项目下载 编辑:程序博客网 时间:2024/06/06 03:28
240. Search a 2D Matrix II
- Search a 2D Matrix II
- 题目描述
- 题意
- 分治法
- 算法描述
- 具体实现
- 复杂度
题目描述
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.
For example,
Consider the following matrix:
[ [1, 4, 7, 11, 15], [2, 5, 8, 12, 19], [3, 6, 9, 16, 22], [10, 13, 14, 17, 24], [18, 21, 23, 26, 30]]
Given target = 5, return true.
Given target = 20, return false.
题意
矩阵从左到右从上到下递增,要求查找某个数是否在矩阵里
分治法
算法描述
从右上角的数num开始与target比较,i记行数,j记列数
- 若num==target,返回true
- 若num>target,说明target比这一列j的数中大于i的都要小,所以j–
- 若num
具体实现
class Solution {public: bool searchMatrix(vector<vector<int>>& matrix, int target) { if (matrix.size() == 0) return false; // get the size of matrix int m = matrix.size(); int n = matrix[0].size(); // find the element int i = 0, j = n-1; while(i < m && j >= 0) { if (matrix[i][j] == target) return true; else if (matrix[i][j] > target) j--; else i++; } return false; // cannot find the target }};
复杂度
时间复杂度
空间复杂度
阅读全文
0 0
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240. Search a 2D Matrix II
- 240.Search a 2D Matrix II
- 深究标准IO的缓存
- C#动态调用C++编写的DLL函数
- Weblogic 12c启动安装程序
- angular js 购物车+删除+总价+总数+个数
- [RK3288][Android6.0] 调试笔记 --- 读取GPU当前频率方法
- 240. Search a 2D Matrix II
- java基础——String和StringBuffer的区别
- 《欢聚时代2017校招笔试题目(PHP工程师类)---错题解析》
- 详细教程:在VMware部署虚拟机
- 非静态成员函数的非法调用
- 【linux学习】常用linux基础指令1
- mysql-1055错误
- +(void)load; +(void)initialize;有什么用处?
- 手机号验证的正则表达式