IF文の記述をシンプルにする方法

いつもお世話になります。
下記のようにIF入れ子で分岐をして3×3×3で27通りの処理をさせたいのですが、もっとシンプルに記述方法があれば御指導お願い致します。

if($asa_ch==1 and $asa_ch_ok ==1){
　if($hiru_ch==1 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
$flag = 1;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 2;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 3;
　　}
　}elseif($hiru_ch==2 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
　　　　　　$flag = 4;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 5;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 6;
　　}
　}elseif($hiru_ch==3 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
$flag = 7;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 8;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 9;
　　}
}elseif($asa_ch==2 and $asa_ch_ok ==1){
　if($hiru_ch==1 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
　　　　　$flag = 10;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 11;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 12;
　　}
　}elseif($hiru_ch==2 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
$flag = 13;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 14;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 15;
　　}
　}elseif($hiru_ch==3 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
　　　　　$flag = 16;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 17;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 18;
　　}
}elseif($asa_ch==3 and $asa_ch_ok ==1){
　if($hiru_ch==1 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
$flag = 19;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 20;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 21;
　　}
　}elseif($hiru_ch==2 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
$flag = 22;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 23;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 24;
　　}
　}elseif($hiru_ch==3 and $hiru_ch_ok == 1){
　　if($yoru_ch ==1 and $hiru_ch_ok ==1){
　　　　　$flag = 25;
　　}elseif($yoru_ch ==2 and $hiru_ch_ok ==1){
$flag = 26;
　　}elseif($yoru_ch ==3 and $hiru_ch_ok ==1){
$flag = 27;
　　}
}
}

No.2 ベストアンサー 回答者： edomin2004 回答日時： 2008/01/08 05:57

＃１です。

if($asa_ch_ok == 1 and $hiru_ch_ok == 1){
　if($asa_ch>=1 and $asa_ch<=3 and $hiru_ch >=1 and $hiru_ch<=3 and $yoru_ch>=1 and $yoru_ch<=3){
　　$flag = ($asa_ch - 1) * 9 + ($hiru_ch - 1) * 3 + $yoru_ch;
　}
}
の方がいいかも…。
（インデントのために全角スペース使ってます。）

この回答へのお礼

edomin2004様
ありがとうございます。
動作を確認し改めて感動しました。
ダラダラと長文になって困っていましたが、
本当にこんなに短くなってすっきりできて感動です。
ありがとうございました。

お礼日時：2008/01/08 11:29

No.1 回答者： edomin2004 回答日時： 2008/01/08 05:33

こういうことでしょうか？

if($asa_ch_ok == 1 and $hiru_ch_ok == 1){
　$flag = ($asa_ch - 1) * 9 + ($hiru_ch - 1) * 3 + $yoru_ch;
}