Merge pull request #1110 from 0xff-dev/1115

Add solution and test-cases for problem 1115

Author: 6boris

leetcode/1101-1200/1115.Print-FooBar-Alternately/README.md

@@ -1,48 +1,53 @@
-# [1. Add Sum][title]
+# [1115. Print FooBar Alternately][title]
 
 ## Description
 
-Given two binary strings, return their sum (also a binary string).
-
-The input strings are both **non-empty** and contains only characters `1` or `0`.
-
-**Example 1:**
-
-```
-Input: a = "11", b = "1"
-Output: "100"
-```
-
-**Example 2:**
-
-```
-Input: a = "1010", b = "1011"
-Output: "10101"
+Suppose you are given the following code:
+
+```cpp
+class FooBar {
+  public void foo() {
+    for (int i = 0; i < n; i++) {
+      print("foo");
+    }
+  }
+
+  public void bar() {
+    for (int i = 0; i < n; i++) {
+      print("bar");
+    }
+  }
+}
 ```
 
-**Tags:** Math, String
+The same instance of `FooBar` will be passed to two different threads:
 
-## 题意
-> 求2数之和
+- thread `A` will call `foo()`, while
+- thread `B` will call `bar()`.
 
-## 题解
+Modify the given program to output "`foobar`" `n` times.
 
-### 思路1
-> 。。。。
 
-```go
+**Example 1:**
 
+```
+Input: n = 1
+Output: "foobar"
+Explanation: There are two threads being fired asynchronously. One of them calls foo(), while the other calls bar().
+"foobar" is being output 1 time.
 ```
 
-### 思路2
-> 思路2
-```go
+**Example 2:**
 
+```
+Input: n = 2
+Output: "foobarfoobar"
+Explanation: "foobar" is being output 2 times.
 ```
 
 ## 结语
 
 如果你同我一样热爱数据结构、算法、LeetCode，可以关注我 GitHub 上的 LeetCode 题解：[awesome-golang-algorithm][me]
 
-[title]: https://leetcode.com/problems/two-sum/description/
+[title]: https://leetcode.com/problems/print-foobar-alternately
 [me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/1101-1200/1115.Print-FooBar-Alternately/Solution.go

@@ -1,9 +1,30 @@
 package Solution
 
-func Solution_1(x bool) bool {
-	return x
+type FooBar struct {
+	n    int
+	a, b chan struct{}
 }
 
-func Solution_2(x bool) bool {
-	return x
+func Solution(n int) *FooBar {
+	f := &FooBar{n: n, a: make(chan struct{}, 1), b: make(chan struct{}, 1)}
+	f.b <- struct{}{}
+	return f
+}
+
+func (fb *FooBar) Foo(printFoo func()) {
+	for i := 0; i < fb.n; i++ {
+		// printFoo() outputs "foo". Do not change or remove this line.
+		<-fb.b
+		printFoo()
+		fb.a <- struct{}{}
+	}
+}
+
+func (fb *FooBar) Bar(printBar func()) {
+	for i := 0; i < fb.n; i++ {
+		// printBar() outputs "bar". Do not change or remove this line.
+		<-fb.a
+		printBar()
+		fb.b <- struct{}{}
+	}
 }

leetcode/1101-1200/1115.Print-FooBar-Alternately/Solution_test.go

@@ -1,48 +1,69 @@
 package Solution
 
 import (
+	"bytes"
 	"fmt"
+	"io"
 	"reflect"
-	"runtime"
-	"strings"
+	"strconv"
+	"sync"
 	"testing"
-
-	"github.com/stretchr/testify/assert"
 )
 
-// Solution func Info
-type SolutionFuncType func(x bool) bool
-
-var SolutionFuncList = []SolutionFuncType{
-	Solution_1,
-	Solution_2,
+func foo(output io.Writer) func() {
+	return func() {
+		fmt.Fprint(output, "foo")
+	}
 }
 
-// Test case info struct
-type Case struct {
-	name   string
-	input  bool
-	expect bool
+func bar(output io.Writer) func() {
+	return func() {
+		fmt.Fprint(output, "bar")
+	}
 }
-
-// Test case
-var cases = []Case{
-	{name: "TestCase 1", input: true, expect: true},
-	{name: "TestCase 2", input: false, expect: false},
+func run(fb *FooBar) string {
+	var wg sync.WaitGroup
+	wg.Add(2)
+	buf := bytes.NewBuffer([]byte{})
+	go func() {
+		defer wg.Done()
+		fb.Foo(foo(buf))
+	}()
+	go func() {
+		defer wg.Done()
+		fb.Bar(bar(buf))
+	}()
+	wg.Wait()
+	return buf.String()
 }
 
-// TestSolution Run test case for all solutions
 func TestSolution(t *testing.T) {
-	ast := assert.New(t)
+	//	测试用例
+	cases := []struct {
+		name   string
+		inputs int
+		expect string
+	}{
+		{"TestCase1", 1, "foobar"},
+		{"TestCase2", 2, "foobarfoobar"},
+	}
 
-	for _, f := range SolutionFuncList {
-		funcName := strings.Split(runtime.FuncForPC(reflect.ValueOf(f).Pointer()).Name(), ".")[1]
-		for _, c := range cases {
-			t.Run(fmt.Sprintf("%s %s", funcName, c.name), func(t *testing.T) {
-				got := f(c.input)
-				ast.Equal(c.expect, got,
-					"func: %v case: %v ", funcName, c.name)
-			})
-		}
+	//	开始测试
+	for i, c := range cases {
+		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
+			got := run(Solution(c.inputs))
+			if !reflect.DeepEqual(got, c.expect) {
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
+					c.expect, got, c.inputs)
+			}
+		})
 	}
 }
+
+// 压力测试
+func BenchmarkSolution(b *testing.B) {
+}
+
+// 使用案列
+func ExampleSolution() {
+}