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disjoint_set.hpp

@@ -1,6 +1,6 @@
 #include <vector>
 
-// Disjoint set trait
+/// Disjoint set trait
 class DisjointSet
 {
 public:

main.cpp

@@ -15,23 +15,39 @@ int main()
     ios_base::sync_with_stdio(0);
     cin.tie(0);
 
+    // Creates a disjoint set that allows undo last action.
+    // It creates a separate array history to allow this.
     auto ds = disjoint_set()->with_undo()->init(2);
     print(ds);
+    // 0 | root 0 | size 1
+    // 1 | root 1 | size 1
 
     ds->merge(0, 1);
     print(ds);
+    // 0 | root 1 | size 2
+    // 1 | root 1 | size 2
 
     ds->undo();
     print(ds);
+    // 0 | root 0 | size 1
+    // 1 | root 1 | size 1
 
-    // This disjoint set doesn't build history vector
+    // This disjoint set doesn't allow to undo (it doesn't build history vector)
+    // but has the same base type that the former disjoint set. It can be passed
+    // to the same function and they expose the same api ...
+    //  with some caveat see below
     ds = disjoint_set()->init(2);
     print(ds);
+    // 0 | root 0 | size 1
+    // 1 | root 1 | size 1
 
     ds->merge(0, 1);
     print(ds);
+    // 0 | root 1 | size 2
+    // 1 | root 1 | size 2
 
-    // This is runtime error since this disjoint set doesn't implement undo
+    // Caveat: This disjoint expose undo function, but it will throw an error if
+    // used since it is not really available.
     // ds->undo();
     // print(ds);