Add solution and test-cases for problem 1079

Author: 0xff-dev

leetcode/1001-1100/1079.Letter-Tile-Possibilities/README.md

@@ -1,28 +1,31 @@
 # [1079.Letter Tile Possibilities][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 have `n`  `tiles`, where each tile has one letter `tiles[i]` printed on it.
+
+Return the number of possible non-empty sequences of letters you can make using the letters printed on those `tiles`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: tiles = "AAB"
+Output: 8
+Explanation: The possible sequences are "A", "B", "AA", "AB", "BA", "AAB", "ABA", "BAA".
 ```
 
-## 题意
-> ...
+**Example 2:**
 
-## 题解
-
-### 思路1
-> ...
-Letter Tile Possibilities
-```go
+```
+Input: tiles = "AAABBC"
+Output: 188
 ```
 
+**Example 3:**
+
+```
+Input: tiles = "V"
+Output: 1
+```
 
 ## 结语
 

leetcode/1001-1100/1079.Letter-Tile-Possibilities/Solution.go

@@ -1,5 +1,23 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(tiles string) int {
+	count := [26]int{}
+	for _, c := range tiles {
+		count[c-'A']++
+	}
+	var dfs func() int
+	dfs = func() int {
+		r := 1
+		for i := 0; i < 26; i++ {
+			if count[i] == 0 {
+				continue
+			}
+			count[i]--
+			r += dfs()
+			count[i]++
+		}
+		return r
+
+	}
+	return dfs() - 1
 }

leetcode/1001-1100/1079.Letter-Tile-Possibilities/Solution_test.go

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs string
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "AAB", 8},
+		{"TestCase2", "AAABBC", 188},
+		{"TestCase3", "V", 1},
 	}
 
 	//	开始测试
@@ -30,10 +30,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }