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in reply to random pairs

#!/usr/bin/perl use warnings; use strict; use List::Util 'shuffle'; my @random; LOOP: { @random = shuffle 0 .. 99; my %unique; for ( 0 .. $#random ) { redo LOOP if $_ == $random[ $_ ] || ++$unique{ $_ < $random[ $ +_ ] ? "$_,$random[$_]" : "$random[$_],$_" } > 1; } } my @pairs = map [ $_, $random[ $_ ] ], 0 .. $#random;

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Re^2: random pairs
by CountZero (Bishop) on Jul 14, 2012 at 12:12 UTC
    You assume that the "predetermined list" is an unbroken sequence of integers from 0 to x. How will you do if it is just a set of integers with duplicates and gaps?

    CountZero

    A program should be light and agile, its subroutines connected like a string of pearls. The spirit and intent of the program should be retained throughout. There should be neither too little or too much, neither needless loops nor useless variables, neither lack of structure nor overwhelming rigidity." - The Tao of Programming, 4.1 - Geoffrey James

    My blog: Imperial Deltronics