第二题
求位于1000~9999中的数,插入运算符号+-*/ 最少一个,并使结果等于该数的逆序。
$i = 1000;
$ii =9999;
@y = ('*','');
while($i <= $ii){
$i =~/(\d)(\d)(\d)(\d)/;
$n = $1;
$m = $2;
$l = $3;
$k = $4;
if($n != 0 && $m != 0 && $l != 0 && $k != 0){
for($o = 0;$o<=1;$o++){
for($p = 0;$p<=1;$p++){
for($q = 0;$q<=1;$q++){
$w = "$n$y[$o]$m$y[$p]$l$y[$q]$k";
if((length "$w") > 4){
$v = eval $w;
if((length "$v") == 4){
if($i eq reverse $v){
print"$i $w\n";
}
}
}
}
}
}
}
$i++;
}