# 搜索二维矩阵

<p>编写一个高效的算法来判断 <code>m x n</code> 矩阵中，是否存在一个目标值。该矩阵具有如下特性：</p><ul>	<li>每行中的整数从左到右按升序排列。</li>	<li>每行的第一个整数大于前一行的最后一个整数。</li></ul><p> </p><p><strong>示例 1：</strong></p><img alt="" src="https://cdn.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0074.Search%20a%202D%20Matrix/images/mat.jpg" style="width: 322px; height: 242px;" /><pre><strong>输入：</strong>matrix = [[1,3,5,7],[10,11,16,20],[23,30,34,60]], target = 3<strong><br />输出：</strong>true</pre><p><strong>示例 2：</strong></p><img alt="" src="https://cdn.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0074.Search%20a%202D%20Matrix/images/mat2.jpg" style="width: 322px; height: 242px;" /><pre><strong>输入：</strong>matrix = [[1,3,5,7],[10,11,16,20],[23,30,34,60]], target = 13<strong><br />输出：</strong>false</pre><p> </p><p><strong>提示：</strong></p><ul>	<li><code>m == matrix.length</code></li>	<li><code>n == matrix[i].length</code></li>	<li><code>1 <= m, n <= 100</code></li>	<li><code>-10<sup>4</sup> <= matrix[i][j], target <= 10<sup>4</sup></code></li></ul>

## template

```java
class Solution {
	public boolean searchMatrix(int[][] matrix, int target) {
		if (matrix.length == 0 || matrix[0].length == 0)
			return false;
		int begin, mid, end;
		begin = mid = 0;
		int len1 = matrix.length, len2 = matrix[0].length;
		end = len1 * len2 - 1;
		while (begin < end) {
			mid = (begin + end) / 2;
			if (matrix[mid / len2][mid % len2] < target)
				begin = mid + 1;
			else
				end = mid;
		}
		return matrix[begin / len2][begin % len2] == target;
	}
}
```

## 答案

```java

```

## 选项

### A

```java

```

### B

```java

```

### C

```java

```