Using flip-flops : 
 my @probs =(0,0.1,0.53,0.51,0.59,0.67,0.2,0.04,0.05,0.56,0.89,0.75);
 my $t;
 print $_ . (",","\n")[$t=1-$t]  
     for  grep {($probs[$_] >=.5 .. $probs[$_]> .5) and $t=!$t }
            0..$#probs

[download]
Output: 
2,4
9,11

[download]
update:graff has pointed out that this code is buggy, because it produces (2,4), instead of (2,5).
Suggestions to fix it are invited. Fixes I can think of involve several lines of code - can anyone do it in 2 ?

     ..to maintain is to slowly feel your soul, sanity and sentience ebb away as you become one with the Evil.

In reply to Re: printing array positions that match a condition by NetWallah
in thread printing array positions that match a condition by coldy

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