Duplicates in array

Author: kumar91gopi

arrays/DuplicatesInArray.rb

@@ -0,0 +1,18 @@
+#Given an array of length n contains elements from 0 to n-1, 
+#Print all the duplicate elements in O(n) time and constant space.
+
+def print_duplicates(a)
+    n=a.length
+    print "Duplicate elements are: "
+    for i in 0...n
+        if a[a[i].abs]<0
+          print "#{a[i].abs} "
+        else
+            a[a[i].abs]= -a[a[i].abs]
+        end
+    end
+  return
+end
+print_duplicates([1, 4, 6, 4, 3, 6, 1])	# => Duplicate elements are: 4 6 1
+    
+