php 怎么判断为顺子，三个相邻的数字

if ($n1+1==$n2 && $n2+1==$n3) {
$shunzi = '顺子';
} else {
if ($n1 - 1 == $n2 && $n2 - 1 == $n3) {
$shunzi = "顺子";
} else {
$shunzi = "非顺子";
}
}

判断n1, n2, n3 是否为顺子

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另一种方法;

$a[1] = rand(0,9);
$a[2] = rand(0,9);
$a[3] = rand(0,9);
$equal = 0;
$adjacent = 0;
foreach($a as $k1 => $v1){
foreach($a as $k2 => $v2){
if($k1!=$k2){
if($v1 == $v2){$equal+=1; $adjacent-=1;}
if(abs($v1-$v2)==1 || abs($v1-$v2)==9){$adjacent+=1;}
}
}
}
$equal = $equal/2;
$adjacent = $adjacent/2;
echo $a[1],$a[2],$a[3],"<br/>\r\n 相等次数:",$equal,"<br/>\r\n 相邻次数:",$adjacent;
if($equal==3){
echo '三对,';
}
if($equal==2){
echo '二对,';
}
if($adjacent==2){
echo '顺子';
}

正则：

$ss = $n1.$n2.$n3;
if(preg_match('/^(0(?=1)|1(?=2)|2(?=3)|3(?=4)|4(?=5)|5(?=6)|6(?=7)|7(?=8)|8(?=9)){2}\d$/',$ss)){
$shunzi = "顺子";
}else{
$shunzi = "非顺子";
}