Jump Game II
<p>You are given a <strong>0-indexed</strong> array of integers <code>nums</code> of length <code>n</code>. You are initially positioned at <code>nums[0]</code>.</p>

<p>Each element <code>nums[i]</code> represents the maximum length of a forward jump from index <code>i</code>. In other words, if you are at <code>nums[i]</code>, you can jump to any <code>nums[i + j]</code> where:</p>

<ul>
	<li><code>0 &lt;= j &lt;= nums[i]</code> and</li>
	<li><code>i + j &lt; n</code></li>
</ul>

<p>Return <em>the minimum number of jumps to reach </em><code>nums[n - 1]</code>. The test cases are generated such that you can reach <code>nums[n - 1]</code>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,3,1,1,4]
<strong>Output:</strong> 2
<strong>Explanation:</strong> The minimum number of jumps to reach the last index is 2. Jump 1 step from index 0 to 1, then 3 steps to the last index.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,3,0,1,4]
<strong>Output:</strong> 2
</pre>

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

<ul>
	<li><code>1 &lt;= nums.length &lt;= 10<sup>4</sup></code></li>
	<li><code>0 &lt;= nums[i] &lt;= 1000</code></li>
	<li>It&#39;s guaranteed that you can reach <code>nums[n - 1]</code>.</li>
</ul>
Greedy; Array; Dynamic Programming
class Solution {
    /**
     * @param Integer[] $nums
     * @return Integer
     */
    function jump($nums) {
        $ans = 0;
        $mx = 0;
        $last = 0;

        for ($i = 0; $i < count($nums) - 1; $i++) {
            $mx = max($mx, $i + $nums[$i]);
            if ($last == $i) {
                $ans++;
                $last = $mx;
            }
        }

        return $ans;
    }
}
