Added max_value_arr file

Added a python file with three various approaches

max_value_arr.py

@@ -0,0 +1,23 @@
+#APPROACH -1
+#SORTING THE INITIAL LIST AND RETURNING THE LAST ELEMENT OF LIST
+def max(arr):
+
+    arr.sort()
+    return arr[-1]
+#APPROACH -2
+#ITERATING THROUGH ALL THE ELEMENTS IN LIST AND COMPARING EACH ELEMENT
+
+def max(arr):
+
+    max_element = arr[0]
+
+    for i in range(len(arr)):
+        if arr[i] > max_element:
+            max_element = arr[i]
+
+    return (max_element)
+
+#APPROACH-3
+#USING INBUILT FUNCTION
+def max(arr):
+    return (max(arr))