leetcode JAVA Search a 2D Matrix 难度系数3 3.25

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.

public class Solution {
   public boolean searchMatrix(int[][] matrix, int target) {
		int row = matrix.length;
		int col = matrix[0].length;
		int[] temp = new int[row * col];
		int count = 0;
		for (int i = 0; i < row; i++) {
			for (int j = 0; j < col; j++) {
				temp[count++] = matrix[i][j];
			}
		}
		int low = 0;
		int high = row * col-1;
		int mid = -1;
		while (low <= high) {
			mid = (low + high) / 2;
			if (temp[mid] == target) {
				return true;
			} else if (temp[mid] > target) {
				high = mid - 1;
			} else {
				low = mid + 1;
			}
		}
		return false;
	}
}

public class Solution {
   public boolean searchMatrix(int[][] matrix, int target) {
		int row = matrix.length;
		int col = matrix[0].length;
		int low = 0;
		int high = row * col - 1;
		int mid = -1;
		while (low <= high) {
			mid = (low + high) / 2;
			if (matrix[mid/col][mid%col] == target) {
				return true;
			} else if (matrix[mid/col][mid%col] > target) {
				high = mid - 1;
			} else {
				low = mid + 1;
			}
		}
		return false;
   }
}

leetcode JAVA Search a 2D Matrix 难度系数3 3.25

原文：http://blog.csdn.net/yiding_he/article/details/18893613