From 1b8ef887fce13dcbb1dec9e55dbb313a38b5272a Mon Sep 17 00:00:00 2001
From: "J. Zhao" <zzjjzzgggg@gmail.com>
Date: Thu, 9 Apr 2020 20:40:04 +0800
Subject: [PATCH] bgraph: avoid adding duplicated edges in addEdge(src, dst)

---
 graph/bgraph.h | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/graph/bgraph.h b/graph/bgraph.h
index af5a162..efcdc2a 100644
--- a/graph/bgraph.h
+++ b/graph/bgraph.h
@@ -126,10 +126,12 @@ class BGraph {
      * Add edge and keep neighbors in ordered vector.
      */
     void addEdge(const int src, const int dst) {
-        addNodeL(src);
-        nodes_L_[src].addNbr(dst);
-        addNodeR(dst);
-        nodes_R_[dst].addNbr(src);
+        if (!isEdge(src, dst)) {
+            addNodeL(src);
+            nodes_L_[src].addNbr(dst);
+            addNodeR(dst);
+            nodes_R_[dst].addNbr(src);
+        }
     }
 
     /**
@@ -170,6 +172,6 @@ class BGraph {
 
 }; /* BGraph */
 
-} /* namespace graph */
+}  // namespace graph::bi
 
 #endif /* __BGRAPH_H__ */