[your code here]

[H. S. Teoh]

// Outputs a randomly selected line from standard input with equal
// likelihood.
import std.random;
import std.stdio;

void main() {
        auto n = 0;
        string choice;
        foreach (line; stdin.byLine()) {
                n++;
                if (uniform(0,n) == 0)
                        choice = line.idup;
        }
        writeln(choice);
}


P.S. Proof that the probability any line is selected is exactly 1/n
(where n is the total number of lines read) is left as an exercise for
the reader. ;-)

P.S.S. The .idup is a bit ugly, but necessary, since apparently byLine()
calls readln() with a static buffer, so choice will be silently
overwritten if the .idup is omitted.


T

-- 
Ruby is essentially Perl minus Wall.