#!/usr/bin/perl

# Description: Check string for unmatching parenthesis 
#
# Last Update: 23 Aug 2011
# Designed by: Dusan U. Baljevic (dusan.baljevic@ieee.org)
# Coded by:    Dusan U. Baljevic (dusan.baljevic@ieee.org)
#
# Copyright 2006-2015 Dusan Baljevic
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

my $s = '((()))()';
my $s1= ')()()()())))(()()()((';
my @ARR = ( $s, $s1 );

my $openp  = '(';
my $closp  = ')';

foreach my $arrel ( @ARR ) {
    print "\nChecking string \"$arrel\"\n";
    my $offset1 = my $offset2 = 0;
    my $count1 = my $count2 = 0;

    my $result1 = index($arrel, $openp, $offset1);
    my $result2 = index($arrel, $closp, $offset2);

    while ($result1 != -1) {
        $count1++;
        $offset1 = $result1 + 1;
        $result1 = index($arrel, $openp, $offset1);
    }

    while ($result2 != -1) {
        $count2++;
        $offset2 = $result2 + 1;
        $result2 = index($arrel, $closp, $offset2);
    }

    if ( $count1 == $count2 ) {
        print "String $arrel contains equal number of open and close parenthesis ($count1)\n";
    }
    else {
        print "String $arrel contains non-equal number of open and close parenthesis ($count1 versus $count2)\n";
    }
}

exit(0);