Medium 74题 Search a 2D Matrix

Question:

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 row.

For example,

Consider the following matrix:

[
[1,   3,  5,  7],
[10, 11, 16, 20],
[23, 30, 34, 50]
]

Given target = 

3

, return 

true

.

Solution:

binary...边界条件调了好半天！！。。太不专心了。。不开心

public class Solution {
public boolean searchMatrix(int[][] matrix, int target) {
int m=matrix.length;
int n=matrix[0].length;
int low=0;
int high=m*n-1;

if(m==0||n==0)
{
return false;
}
while(low<=high)
{
int mid=(high-low)/2+low;
if(target>matrix[mid/n][mid%n])
low=mid+1;
else if(target<matrix[mid/n][mid%n])
high=mid-1;
else
return true;
}
return false;
}
}