slightly friendlier graph initialization

1 files changed, 11 insertions, 12 deletions

diff --git a/lib/src/graph.cpp b/lib/src/graph.cpp
index e76947b..e5f374e 100644
--- a/lib/src/graph.cpp
+++ b/lib/src/graph.cpp
@@ -7,10 +7,10 @@ graph::graph(unsigned int L) {
   unsigned int ne = pow(L, 2);
 
   vertices.resize(nv);
-  edges.resize(ne);
+  edges.reserve(ne);
 
   dual_vertices.resize(nv);
-  dual_edges.resize(ne);
+  dual_edges.reserve(ne);
 
   for (unsigned int i = 0; i < nv; i++) {
     vertices[i].r.x = dx * ((1 + i / (L / 2)) % 2 + 2 * (i % (L / 2)));
@@ -20,19 +20,18 @@ graph::graph(unsigned int L) {
     dual_vertices[i].r.y = dx * (i / (L / 2));
   }
 
-  for (unsigned int i = 0; i < ne; i++) {
-    unsigned int x = i / L;
-    unsigned int y = i % L;
+  for (unsigned int x = 0; x < L; x++) {
+    for (unsigned int y = 0; y < L; y++) {
+      unsigned int v1 = (L * x) / 2 + ((y + x % 2) / 2) % (L / 2);
+      unsigned int v2 = ((L * (x + 1)) / 2 + ((y + (x + 1) % 2) / 2) % (L / 2)) % nv;
 
-    unsigned int v1 = (L * x) / 2 + ((y + x % 2) / 2) % (L / 2);
-    unsigned int v2 = ((L * (x + 1)) / 2 + ((y + (x + 1) % 2) / 2) % (L / 2)) % nv;
+      edges.push_back({v1, v2});
 
-    edges[i] = {v1, v2};
+      unsigned int dv1 = (L * x) / 2 + ((y + (x + 1) % 2) / 2) % (L / 2);
+      unsigned int dv2 = ((L * (x + 1)) / 2 + ((y + x % 2) / 2) % (L / 2)) % nv;
 
-    unsigned int dv1 = (L * x) / 2 + ((y + (x + 1) % 2) / 2) % (L / 2);
-    unsigned int dv2 = ((L * (x + 1)) / 2 + ((y + x % 2) / 2) % (L / 2)) % nv;
-
-    dual_edges[i] = {dv1, dv2};
+      dual_edges.push_back({dv1, dv2});
+    }
   }
 }