X-Original-To: [EMAIL PROTECTED] Mailing-List: contact [EMAIL PROTECTED]; run by ezmlm X-Spam-Status: No, hits=0.3 required=7.0 tests=NO_REAL_NAME X-Spam-Check-By: la.mx.develooper.com Date: Tue, 20 Apr 2004 19:57:27 -0400 (EDT) From: <[EMAIL PROTECTED]>
We want to find out the first position $n at which strings $x and $y differ. If $x eq $y, then $n is undef. If $x ne $y but $x is a prefix (aka initial segment) of $y, then $n should be equal to length $x. The operation must preserve both $x and $y (i.e. destructive operations are disallowed). By way of baseline, here's an utterly uninspired solution: $n=0;while(($c=substr($x,$n,1)||undef $n) && $c eq substr($y,$n++,1)){;} It's worse than uninspired, actually. It's wrong. kj