添加 0059.螺旋矩阵II PHP版本

problems/0059.螺旋矩阵II.md

@@ -426,6 +426,48 @@ impl Solution {
 }
 ```
 
+PHP:
+```php
+class Solution {
+    /**
+     * @param Integer $n
+     * @return Integer[][]
+     */
+    function generateMatrix($n) {
+        // 初始化数组
+        $res = array_fill(0, $n, array_fill(0, $n, 0));
+        $mid = $loop = floor($n / 2);
+        $startX = $startY = 0;
+        $offset = 1;
+        $count = 1;
+        while ($loop > 0) {
+            $i = $startX;
+            $j = $startY;
+            for (; $j < $startY + $n - $offset; $j++) {
+                $res[$i][$j] = $count++;
+            }
+            for (; $i < $startX + $n - $offset; $i++) {
+                $res[$i][$j] = $count++;
+            }
+            for (; $j > $startY; $j--) {
+                $res[$i][$j] = $count++;
+            }
+            for (; $i > $startX; $i--) {
+                $res[$i][$j] = $count++;
+            }
+            $startX += 1;
+            $startY += 1;
+            $offset += 2;
+            $loop--;
+        }
+        if ($n % 2 == 1) {
+            $res[$mid][$mid] = $count;
+        }
+        return $res;
+    }
+}
+```
+
 
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 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)