240. Search a 2D Matrix II
Description 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.
Analysi 这道题的题意很简单，就是给定一个数，然后寻找这个数是不是存在于给定的二维数组中，如果存在则返回true，不存在则返回false。这道题我一开始尝试了一下直接利用两个循环可不可以accepted，结果发现是可以的= = 。下面是我的代码。
Code
class Solution { public: bool searchMatrix(vector<vector<int>>& matrix, int target) { int len = matrix.size(); if(len == 0) return false; int len2 = matrix[0].size(); if(len2==0) return false; int res = 0; for(int i = 0 ;i < len;++i){ for(int j = 0 ; j<len2;++j){ if(target == matrix[i][j]) { return true; } } } return false; } };