fix random generator capacity, add Dinic's algo, add options for filtering empty flows & displaying residual graph

src/random_generator.rs

@@ -1,3 +1,4 @@
+use petgraph::data::Build;
 use petgraph::stable_graph::{StableGraph, NodeIndex};
 use petgraph::{Directed};
 use egui_graphs::{default_edge_transform, default_node_transform, to_graph_custom, DefaultEdgeShape, DefaultNodeShape, Graph};
@@ -70,9 +71,10 @@ impl MaxflowProblem {
                 // otherwise insert the edge and its residual edge
                 inserted_edges.push((node1, node2));
                 inserted_edges.push((node2, node1));
-                let capacity: u64 = rng.gen_range(1..=max_capacity);
-                graph.add_edge(node1, node2, (0, capacity));
-                graph.add_edge(node2, node1, (0, capacity));
+                let capacity1: u64 = rng.gen_range(1..=max_capacity);
+                let capacity2: u64 = rng.gen_range(1..=max_capacity);
+                graph.add_edge(node1, node2, (0, capacity1));
+                graph.add_edge(node2, node1, (0, capacity2));
             }
         }
 
@@ -101,6 +103,14 @@ impl MaxflowProblem {
         }
     }
 
+    // set all flows back to zero
+    pub fn reset_flow(&mut self) {
+        for edge in self.g.edge_indices().collect::<Vec<_>>() {
+            let weight = self.g.edge_weight_mut(edge).expect("edge not found");
+            (*weight).0 = 0;
+        }
+    }
+
     pub fn to_gui_graph(&self) -> Graph<(f32, f32), (u64, u64), Directed, u32, DefaultNodeShape, CustomEdgeShape> {
         let mut graph = to_graph_custom(&self.g,
             |n| {