From f2cdf4707007a3df2b400092277bcedcb85bc0b3 Mon Sep 17 00:00:00 2001
From: lgray <lindsey.gray@gmail.com>
Date: Thu, 2 Jun 2016 11:44:47 -0500
Subject: [PATCH] run forward and backwards checks when looking for links,
 minor performance penalty

---
 RecoParticleFlow/PFProducer/src/PFBlockAlgo.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/RecoParticleFlow/PFProducer/src/PFBlockAlgo.cc b/RecoParticleFlow/PFProducer/src/PFBlockAlgo.cc
index cd60d2473687c..1cd8a453f57eb 100644
--- a/RecoParticleFlow/PFProducer/src/PFBlockAlgo.cc
+++ b/RecoParticleFlow/PFProducer/src/PFBlockAlgo.cc
@@ -164,7 +164,8 @@ void PFBlockAlgo::findBlocks() {
   QuickUnion qu(bare_elements_.size());
   const auto elem_size = bare_elements_.size();
   for( unsigned i = 0; i < elem_size; ++i ) {
-    for( unsigned j = 0; j < i; ++j ) {
+    for( unsigned j = 0; j < elem_size; ++j ) {
+      if( j == i ) continue;
       if( !_linkTests[_linkTestSquare[bare_elements_[i]->type()][bare_elements_[j]->type()]] ) {
         j = ranges_[bare_elements_[j]->type()].second;
         continue;