【LeetCode】Search a 2D Matrix

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.

http://oj.leetcode.com/problems/search-a-2d-matrix/

public class Solution {
    public boolean searchMatrix(int[][] matrix, int target) {
        int row=matrix.length;
        int col=matrix[0].length;
        if(row==0||col==0||matrix[0][0]>target||matrix[row-1][col-1]<target){
            return false;
        }
        int in =-1;
        for(int i=1;i<row;i++){
            if(matrix[i][0]>target){
                in = i-1;
                break;
            }
        }
        if(in==-1){
            in = row-1;
        }
        
        for(int x=0;x<col;x++){
            if(matrix[in][x]==target){
                return true;
            }
        }
        
        return false;
        
    }
}