87 lines
2.2 KiB
Raku
Executable File
87 lines
2.2 KiB
Raku
Executable File
#!/usr/bin/env perl6
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# Exercise 2.2.1
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sub sphere-volume($r) { 4/3 * π * $r³ }
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# Exercise 3.1
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# Notice the operator precedence
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sub rjust(Str $str, Int $width = 70) { ' ' x $width - $str.chars ~ $str }
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#put rjust("Larry Wall", 80);
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# Exercise 3.2
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sub print-twice($str) {
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put $str;
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put $str
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}
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sub do-twice(&code, $arg) {
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code $arg;
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code $arg
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}
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#do-twice(&print-twice, "What's up doc");
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sub do-four(&code, $arg) { do-twice { do-twice &code, $_ }, $arg }
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# Exercise 3.3
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sub grid(Int $rows=2, Int $cols=2, Int $side=4) {
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(('+' for 0..$cols).join((' ' for 0..$side).join('-'))~"\n" for 0..$rows)
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.join((('|' for 0..$cols).join(' ' x $side*2 + 1)~"\n") x $side)
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}
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#print grid(4, 4);
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# Exercise 4.2
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sub check-fermat(Int $a, Int $b, Int $c, Int $n) {
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return if $n <= 2;
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if $a**$n + $b**$n == $c**$n {
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put "Holy smokes, Fermat was wrong!"
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} else {
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put "No, that doesn't work."
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}
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}
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# Exercise 4.3
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sub is-triangle($a, $b, $c) { ([-] reverse sort $a, $b, $c) < 0 }
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# Exercise 4.4
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sub fibonacci(Int $n, Int $a = 0, Int $b = 1) {
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return $a if $n <= 0; #put $a;
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fibonacci $n - 1, $b, $a + $b
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}
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#put fibonacci 20;
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sub hypotenuse($a, $o) { sqrt $a² + $o² }
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#put hypotenuse 3, 4;
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# Exercise 5.2
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multi ack(0, Int $n) { $n + 1 }
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multi ack(Int $m where * > 0, 0) { ack $m - 1, 1 }
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multi ack(Int $m where * > 0, Int $n where * > 0) {
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ack $m - 1, ack($m, $n - 1)
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}
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#put ack 3, 4;
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# Exercise 5.3
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sub is-palindrome(Str $str) { $str eq $str.flip }
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# Exercise 5.4
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sub is-power-of($a, $b) { { $_ == $_.Int }(log $a, $b) }
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# Exercise 5.5: gcd is a built-in operator
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# Exercise 6.1
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sub my-sqrt($a, $epsilon = 0.000_000_1, $x = $a) {
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return $x if abs $x² - $a < $epsilon;
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my-sqrt $a, $epsilon, ($x + $a/$x) / 2
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}
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# Exercise 6.2
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sub factorial(Int $n) { [*] 1..$n }
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sub estimate-pi {
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my $factor = 2 * 2.sqrt / 9801;
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sub Srinivasa-Ramanujan($k = 1, $current = 1103, $result = 1103) {
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my $next = factorial($k * 4) * (1103 + $k*26390)
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/ factorial($k)⁴ / 396**($k*4);
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return $result + $next if $factor * $next < 10**-15;
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Srinivasa-Ramanujan $k + 1, $next, $result + $next;
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}
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1 / $factor / Srinivasa-Ramanujan
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}
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#put abs estimate-pi() - pi;
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