Search a 2D Matrix II
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.
采用分治发，用上题的方法二代码即可，都不需要改的。
1 class Solution { 2 public: 3 bool searchMatrix(vector<vector<int>>& matrix, int target) { 4 if(matrix.size()==0 || matrix[0].size()==0) return false; 5 int m=matrix.size(),n=matrix[0].size(); 6 int row=0,col=n-1; 7 while(row<m && col>=0) 8 { 9 if(matrix[row][col]==target) return true; 10 else if(matrix[row][col]<target) row++; 11 else col--; 12 } 13 return false; 14 } 15 };