添加 0202.快乐数 PHP版本

problems/0202.快乐数.md

@@ -223,6 +223,37 @@ func isHappy(_ n: Int) -> Bool {
 }
 ```
 
+PHP:
+```php
+class Solution {
+    /**
+     * @param Integer $n
+     * @return Boolean
+     */
+    function isHappy($n) {
+        // use a set to record sum
+        // whenever there is a duplicated, stop
+        // == 1 return true, else false
+        $table = [];
+        while ($n != 1 && !isset($table[$n])) {
+            $table[$n] = 1;
+            $n = self::getNextN($n);
+        }
+        return $n == 1;
+    }
+
+    function getNextN(int $n) {
+        $res = 0;
+        while ($n > 0) {
+            $temp = $n % 10;
+            $res += $temp * $temp;
+            $n = floor($n / 10);
+        }
+        return $res;
+    }
+}
+```
+
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