string insertString = candAln.substr(leftIndex+1,rightIndex-leftIndex-1);
string rightCandidateString = candAln.substr(rightIndex+rightRoom);
candAln = leftCandidateString + insertString + rightCandidateString;
string insertString = candAln.substr(leftIndex+1,rightIndex-leftIndex-1);
string rightCandidateString = candAln.substr(rightIndex+rightRoom);
candAln = leftCandidateString + insertString + rightCandidateString;