Merge pull request #230 from 0xff-dev/389

Add solution and test-cases for problem 389

Author: 6boris

leetcode/301-400/0389.Find-the-Difference/README.md

@@ -1,28 +1,25 @@
 # [389.Find the Difference][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+You are given two strings `s` and `t`.
+
+String `t` is generated by random shuffling string `s` and then add one more letter at a random position.
+
+Return the letter that was added to `t`. 
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: s = "abcd", t = "abcde"
+Output: "e"
+Explanation: 'e' is the letter that was added.
 ```
 
-## 题意
-> ...
-
-## 题解
-
-### 思路1
-> ...
-Find the Difference
-```go
+**Example 2:**
+```
+Input: s = "", t = "y"
+Output: "y"
 ```
-
 
 ## 结语
 

leetcode/301-400/0389.Find-the-Difference/Solution.go

@@ -1,5 +1,9 @@
 package Solution
 
-func Solution(x bool) bool {
-return x
+func Solution(s, t string) byte {
+start := uint8(0)
+for _, b := range append([]byte(s), t...) {
+start ^= b
+}
+return byte(start)
 }

leetcode/301-400/0389.Find-the-Difference/Solution_test.go

@@ -10,21 +10,20 @@ func TestSolution(t *testing.T) {
 //	测试用例
 cases := []struct {
 name string
-inputs bool
-expect bool
+s, t string
+expect byte
 }{
-{"TestCase", true, true},
-{"TestCase", true, true},
-{"TestCase", false, false},
+{"TestCase1", "abcd", "abcde", 'e'},
+{"TestCase2", "", "y", 'y'},
 }
 
 //	开始测试
 for i, c := range cases {
 t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-got := Solution(c.inputs)
+got := Solution(c.s, c.t)
 if !reflect.DeepEqual(got, c.expect) {
-t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-c.expect, got, c.inputs)
+t.Fatalf("expected: %v, but got: %v, with inputs: %v,%v",
+c.expect, got, c.s, c.t)
 }
 })
 }