add day 27 challenge

04- April/27- Bulb Switcher/27- Bulb Switcher (Noura Algohary).cpp

@@ -0,0 +1,12 @@
+// Author: Noura Algohary
+
+class Solution {
+public:
+    int bulbSwitch(int n) {
+        // bulbs are counted (turned on) when it have odd number of divisors
+        // only numbers with perfect square roots have odd divisors
+        // to count the number of perfect square roots in n,
+        // it must be equal to sqrt(n)
+        return sqrt(n);
+    }
+};

04- April/27- Bulb Switcher/27- Bulb Switcher (Noura Algohary).py

@@ -0,0 +1,11 @@
+# Author: Noura Algohary
+
+class Solution:
+    def bulbSwitch(self, n: int) -> int:
+        # bulbs are counted (turned on) when it have odd number of divisors
+        # only numbers with perfect square roots have odd divisors
+        # to count the number of perfect square roots in n,
+        # it must be equal to sqrt(n)
+
+        return int(n ** 0.5)
+