From 75f80ae39ff975fa46721a925d0a8d41fab95245 Mon Sep 17 00:00:00 2001
From: stephen mcquay <stephen@mcquay.me>
Date: Fri, 4 May 2018 21:45:21 -0700
Subject: [PATCH] init

---
 LICENSE   | 20 ++++++++++++++++++++
 README.md |  3 +++
 main.go   | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+)
 create mode 100644 LICENSE
 create mode 100644 README.md
 create mode 100644 main.go

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..5996d0b
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,20 @@
+MIT License
+Copyright (c) 2018 Stephen McQuay
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..1583f42
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+# smerge
+
+This answers an interview question
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..7682e49
--- /dev/null
+++ b/main.go
@@ -0,0 +1,56 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"sort"
+	"sync"
+	"time"
+)
+
+func main() {
+	for i := range merge(source(5), source(10), source(20)) {
+		fmt.Printf("%20d\n", i)
+	}
+}
+
+func source(c int) <-chan int {
+	out := make(chan int)
+	go func() {
+		vals := make([]int, c)
+		src := rand.New(rand.NewSource(time.Now().UnixNano()))
+		for i := 0; i < c; i++ {
+			vals[i] = src.Int()
+		}
+
+		sort.Ints(vals)
+
+		for _, i := range vals {
+			out <- i
+		}
+		close(out)
+	}()
+	return out
+}
+
+func merge(cs ...<-chan int) <-chan int {
+	wg := sync.WaitGroup{}
+	out := make(chan int)
+
+	output := func(c <-chan int) {
+		for n := range c {
+			out <- n
+		}
+		wg.Done()
+	}
+
+	wg.Add(len(cs))
+	for _, c := range cs {
+		go output(c)
+	}
+	go func() {
+		wg.Wait()
+		close(out)
+	}()
+	return out
+}