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# abitdodgy/javascript.js Secret

Last active February 9, 2016 00:12
Project Euler #6 solution code samples using Swift, Ruby, and JavaScript. Find full article here: http://mohamad.im
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 // // Using MapReduce // function arrayOfNumbers(n, square) { return Array.apply(null, Array(n)).map(function (e, i) { i += 1; return i * (square ? i : 1); }); } function difference(n) { var sumOfSquares = arrayOfNumbers(n, true).reduce(function (a, b) { return a + b; }); var squareOfSum = arrayOfNumbers(n).reduce(function (a, b) { return a + b; }); squareOfSum *= squareOfSum; return squareOfSum - sumOfSquares; } var start = performance.now(); console.log(difference(125000)); var finish = performance.now(); console.log("MapReduce 125,000 finished in " + (finish - start) / 1000) // // Using while Loop // function diff(n) { var sumOfSquares = squareOfSum = 0; while(n) { sumOfSquares += n * n, squareOfSum += n, n--; } squareOfSum *= squareOfSum; return squareOfSum - sumOfSquares; } var start = performance.now(); console.log(diff(1000000000)); var finish = performance.now(); console.log("Loop 1,000,000,000 finished in " + (finish - start) / 1000)
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 require 'benchmark' def map_reduce(n) (1..n).reduce(:+)**2 - (1..n).map { |n| n**2 }.reduce(:+) end def enum(n) sumOfSquares = squareOfSum = 0 n.downto 1 do |i| squareOfSum += i; sumOfSquares += i * i end (squareOfSum *= squareOfSum) - sumOfSquares end def while_loop(n) sumOfSquares = squareOfSum = 0 while n > 0 squareOfSum += n; sumOfSquares += n * n; n -= 1 end (squareOfSum *= squareOfSum) - sumOfSquares end def induction(n) (n * (n + 1) / 2)**2 - (n * (n + 1)) * ((n * 2) + 1) / 6 end iterations = 10_000_000 puts "Benchmarking with #{iterations} iterations" Benchmark.bm do |bm| bm.report "MapReduce" do map_reduce(iterations) end bm.report "Enum " do enum(iterations) end bm.report "Loop " do while_loop(iterations) end bm.report "Induction" do induction(1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000) end end # Benchmarking with 10000000 iterations # user system total real # MapReduce 2.890000 0.030000 2.920000 ( 2.928501) # Enum 1.610000 0.010000 1.620000 ( 1.611081) # Loop 1.200000 0.000000 1.200000 ( 1.201676) # Induction 0.000000 0.000000 0.000000 ( 0.000010)
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 // // Functional approach // func diff(n: Int) -> Int { let array = [Int](1...n) let sumOfSquares = array.map({ \$0 * \$0 }).reduce(0, +) let sum = array.reduce(0, +) let squareOfSum = sum * sum return squareOfSum - sumOfSquares } // // Using a loop // func loopDiff(var i: Int) -> Int { var sumOfSquares = 0; var squareOfSum = 0 while i > 0 { sumOfSquares += i * i; squareOfSum += i; i-- } squareOfSum *= squareOfSum return squareOfSum - sumOfSquares } let startTime = CFAbsoluteTimeGetCurrent() let result = loopDiff(10000) let timeElapsed = CFAbsoluteTimeGetCurrent() - startTime println("Time elapsed : \(timeElapsed) s") println(result)
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