Kolakoski

Score: 57.18 (pass)

#!perl
s/.?/$ARGV[1&pos]x($&||1)/geuntil/.{$ARGV[2]}/;print$&,$/

Score: 68.18 (pass)

#!perl -l
print map{push@$,($ARGV[--$_%2])x($@=$$[$_]||$ARGV[$_]);$@}1..pop

Score: 80.17 (pass)

#!perl -l
($-,$*)=@ARGV;print map{push@_,(--$_%2?$*:$-)x($/=$_?$_[$_]||$*:$-);$/}1..pop

Score: 83.30 (pass)

#!perl -l
($x,$y,$z)=@ARGV;print map{push@x,($_%2?$y:$x)x($x[$_]or$_?$y:$x);$x[$_]}0..$z-1

Score: 84.32 (pass)

#!perl -l
($x,$y,$z)=@ARGV;push@x,($_%2?$y:$x)x($x[$_]or$_?$y:$x)for 0..$z;print@x[0..$z-1]

Score: 90.31 (pass)

#!perl -l
($x,$y,$z)=@ARGV;push@x,($i%2?$y:$x)x($x[$i++]or $i%2?$x:$y)while@x<$z;print@x[0..$z-1]