fix import issues by using pragma once

Assignment_1/adt_set.cpp

@@ -1,3 +1,5 @@
+#pragma once
+
 #include<iostream>
 #include<set>
 #include<stdexcept>

Assignment_1/concurrent_set.cpp

@@ -1,6 +1,8 @@
+#pragma once
+
 #include <mutex>
-//#include"set.cpp"
+#include"set.cpp"
-//#include"adt_set.cpp"
+#include"adt_set.cpp"
 
 class ConcurrentSet {
     Set cset;

Assignment_1/set.cpp

@@ -1,10 +1,12 @@
+#pragma once
+
 #include<iostream>
 #include<thread>
 #include <algorithm>
 #include <queue>
 #include <mutex>
 #include <assert.h>  
-//#include"adt_set.cpp"
+#include"adt_set.cpp"
 
 
 class Node {