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ListGraph::Snapshot Class Reference

Detailed Description

Class to make a snapshot of the graph and restore it later.

The newly added nodes and edges can be removed using the restore() function.

Note
After a state is restored, you cannot restore a later state, i.e. you cannot add the removed nodes and edges again using another Snapshot instance.
Warning
Node and edge deletions and other modifications (e.g. changing the end-nodes of edges or contracting nodes) cannot be restored. These events invalidate the snapshot. However, the edges and nodes that were added to the graph after making the current snapshot can be removed without invalidating it.

#include <lemon/list_graph.h>

Public Member Functions

 Snapshot ()
 Default constructor. More...
 
 Snapshot (ListGraph &gr)
 Constructor that immediately makes a snapshot. More...
 
void save (ListGraph &gr)
 Make a snapshot. More...
 
void restore ()
 Undo the changes until the last snapshot. More...
 
bool valid () const
 Returns true if the snapshot is valid. More...
 

Constructor & Destructor Documentation

Snapshot ( )
inline

Default constructor. You have to call save() to actually make a snapshot.

Snapshot ( ListGraph gr)
inline

This constructor immediately makes a snapshot of the given graph.

Member Function Documentation

void save ( ListGraph gr)
inline

This function makes a snapshot of the given graph. It can be called more than once. In case of a repeated call, the previous snapshot gets lost.

void restore ( )
inline

This function undos the changes until the last snapshot created by save() or Snapshot(ListGraph&).

Warning
This method invalidates the snapshot, i.e. repeated restoring is not supported unless you call save() again.
bool valid ( ) const
inline

This function returns true if the snapshot is valid.