diff --git a/Segment.cpp b/Segment.cpp
index 8e6fff9..41710cb 100644
--- a/Segment.cpp
+++ b/Segment.cpp
@@ -66,7 +66,6 @@ namespace CppJieba
 
 	string Segment::_utf8ToUni(const string& utfStr)
 	{
-		char logBuf[bufSize];
 		string uniStr = utf8ToUnicode(utfStr);
 
 		if(uniStr.empty())
diff --git a/Trie.cpp b/Trie.cpp
index a9027ce..c16651a 100644
--- a/Trie.cpp
+++ b/Trie.cpp
@@ -368,21 +368,29 @@ namespace CppJieba
 		for(size_t i = 0; i < _nodeInfoVec.size(); i++)
 		{
 			_totalCount += _nodeInfoVec[i].count;
-			//cout<<_nodeInfoVec[i].word<<_nodeInfoVec[i].count<<endl;
+		}
+
+		if(0 == _totalCount)
+		{
+			LogError("_totalCount == 0 .");
+			return false;
 		}
 		
 		//normalize
-		for(size_t i = 0; i < _nodeInfoVec.size(); i++)
+		for(uint i = 0; i < _nodeInfoVec.size(); i++)
 		{
 			TrieNodeInfo& nodeInfo = _nodeInfoVec[i];
+			if(0 == nodeInfo.count)
+			{
+				LogFatal("nodeInfo.count == 0!");
+				return false;
+			}
 			nodeInfo.weight = log(double(nodeInfo.count)/double(_totalCount));
-			//cout<<_nodeInfoVec[i].weight<<endl;
 			if(_minWeight > nodeInfo.weight)
 			{
 				_minWeight = nodeInfo.weight;
 			}
 		}
-		//cout<<_minWeight<<endl;
 		
 		return true;
 	}