Search a 2D Matrix II
<p>Write an efficient algorithm that searches for a value <code>target</code> in an <code>m x n</code> integer matrix <code>matrix</code>. This matrix has the following properties:</p>

<ul>
	<li>Integers in each row are sorted in ascending from left to right.</li>
	<li>Integers in each column are sorted in ascending from top to bottom.</li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0200-0299/0240.Search%20a%202D%20Matrix%20II/images/searchgrid2.jpg" style="width: 300px; height: 300px;" />
<pre>
<strong>Input:</strong> 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]], target = 5
<strong>Output:</strong> true
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0200-0299/0240.Search%20a%202D%20Matrix%20II/images/searchgrid.jpg" style="width: 300px; height: 300px;" />
<pre>
<strong>Input:</strong> 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]], target = 20
<strong>Output:</strong> false
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>m == matrix.length</code></li>
	<li><code>n == matrix[i].length</code></li>
	<li><code>1 &lt;= n, m &lt;= 300</code></li>
	<li><code>-10<sup>9</sup> &lt;= matrix[i][j] &lt;= 10<sup>9</sup></code></li>
	<li>All the integers in each row are <strong>sorted</strong> in ascending order.</li>
	<li>All the integers in each column are <strong>sorted</strong> in ascending order.</li>
	<li><code>-10<sup>9</sup> &lt;= target &lt;= 10<sup>9</sup></code></li>
</ul>
Array; Binary Search; Divide and Conquer; Matrix
func searchMatrix(matrix [][]int, target int) bool {
	for _, row := range matrix {
		j := sort.SearchInts(row, target)
		if j < len(matrix[0]) && row[j] == target {
			return true
		}
	}
	return false
}