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55 lines
1.4 KiB
Perl
55 lines
1.4 KiB
Perl
for ( $i = 0; $i < 15; ++$i ) {
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$array[ $i ] = 2 * $i;
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}
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print "Enter an integer search key: ";
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chomp ( $searchKey = <STDIN> );
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print "\n";
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for ( $i = 0; $i < @array; ++$i ) {
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print $i < 10 ? " $i " : " $i ";
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}
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print "\n", "-" x ( 4 * @array ), "\n";
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$found = 0; # search while !$found
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$lowIndex = 0; # start index for search
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$highIndex = $#array; # end index for search
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while ( $lowIndex <= $highIndex && !$found ) {
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$middleIndex = ( $lowIndex + $highIndex ) / 2;
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for ( $i = 0; $i < @array; ++$i ) {
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if ( $i < $lowIndex || $i > $highIndex ) {
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print " ";
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}
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elsif ( $i == $middleIndex ) {
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print $array[ $i ] < 10 ? " $array[ $i ]*" : " $array[ $i ]*";
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}
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else {
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print $array[ $i ] < 10 ? " $array[ $i ] " : " $array[ $i ] ";
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}
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}
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print "\n";
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if ( $searchKey == $array[ $middleIndex ] ) { # match
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$index = $middleIndex;
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$found = 1;
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}
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elsif ( $searchKey < $array[ $middleIndex ] ) {
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$highIndex = $middleIndex - 1; # search low end of array
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}
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else {
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$lowIndex = $middleIndex + 1; # search high end of array
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}
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}
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# display results
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if ( $found ) { # $found == 1
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print "\nFound $searchKey at subscript $index \n";
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}
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else { # $found == 0
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print "\n$searchKey not found \n";
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} |