// run // Copyright 2009 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // Solve the 2,3,5 problem (print all numbers with 2, 3, or 5 as factor) using channels. // Test the solution, silently. package main type T chan uint64 func M(f uint64) (in, out T) { in = make(T, 100) out = make(T, 100) go func(in, out T, f uint64) { for { out <- f*<-in } }(in, out, f) return in, out } func min(xs []uint64) uint64 { m := xs[0] for i := 1; i < len(xs); i++ { if xs[i] < m { m = xs[i] } } return m } func main() { F := []uint64{2, 3, 5} var n = len(F) OUT := []uint64{ 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 25, 27, 30, 32, 36, 40, 45, 48, 50, 54, 60, 64, 72, 75, 80, 81, 90, 96, 100, 108, 120, 125, 128, 135, 144, 150, 160, 162, 180, 192, 200, 216, 225, 240, 243, 250, 256, 270, 288, 300, 320, 324, 360, 375, 384, 400, 405, 432, 450, 480, 486, 500, 512, 540, 576, 600, 625, 640, 648, 675, 720, 729, 750, 768, 800, 810, 864, 900, 960, 972, 1000, 1024, 1080, 1125, 1152, 1200, 1215, 1250, 1280, 1296, 1350, 1440, 1458, 1500, 1536, 1600} x := uint64(1) ins := make([]T, n) outs := make([]T, n) xs := make([]uint64, n) for i := 0; i < n; i++ { ins[i], outs[i] = M(F[i]) xs[i] = x } for i := 0; i < len(OUT); i++ { for i := 0; i < n; i++ { ins[i] <- x } for i := 0; i < n; i++ { if xs[i] == x { xs[i] = <-outs[i] } } x = min(xs) if x != OUT[i] { println("bad: ", x, " should be ", OUT[i]) panic("235") } } }