1 // run 2 3 // Copyright 2009 The Go Authors. All rights reserved. 4 // Use of this source code is governed by a BSD-style 5 // license that can be found in the LICENSE file. 6 7 // Solve the 2,3,5 problem (print all numbers with 2, 3, or 5 as factor) using channels. 8 // Test the solution, silently. 9 10 package main 11 12 type T chan uint64 13 14 func M(f uint64) (in, out T) { 15 in = make(T, 100) 16 out = make(T, 100) 17 go func(in, out T, f uint64) { 18 for { 19 out <- f*<-in 20 } 21 }(in, out, f) 22 return in, out 23 } 24 25 26 func min(xs []uint64) uint64 { 27 m := xs[0] 28 for i := 1; i < len(xs); i++ { 29 if xs[i] < m { 30 m = xs[i] 31 } 32 } 33 return m 34 } 35 36 37 func main() { 38 F := []uint64{2, 3, 5} 39 var n = len(F) 40 OUT := []uint64{ 41 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 25, 27, 30, 32, 36, 42 40, 45, 48, 50, 54, 60, 64, 72, 75, 80, 81, 90, 96, 100, 108, 120, 125, 43 128, 135, 144, 150, 160, 162, 180, 192, 200, 216, 225, 240, 243, 250, 44 256, 270, 288, 300, 320, 324, 360, 375, 384, 400, 405, 432, 450, 480, 45 486, 500, 512, 540, 576, 600, 625, 640, 648, 675, 720, 729, 750, 768, 46 800, 810, 864, 900, 960, 972, 1000, 1024, 1080, 1125, 1152, 1200, 1215, 47 1250, 1280, 1296, 1350, 1440, 1458, 1500, 1536, 1600} 48 49 x := uint64(1) 50 ins := make([]T, n) 51 outs := make([]T, n) 52 xs := make([]uint64, n) 53 for i := 0; i < n; i++ { 54 ins[i], outs[i] = M(F[i]) 55 xs[i] = x 56 } 57 58 for i := 0; i < len(OUT); i++ { 59 for i := 0; i < n; i++ { 60 ins[i] <- x 61 } 62 63 for i := 0; i < n; i++ { 64 if xs[i] == x { 65 xs[i] = <-outs[i] 66 } 67 } 68 69 x = min(xs) 70 if x != OUT[i] { 71 println("bad: ", x, " should be ", OUT[i]) 72 panic("235") 73 } 74 } 75 } 76
