Add solution and test-cases for problem 3333

Author: 0xff-dev

leetcode/3301-3400/3333.Find-the-Original-Typed-String-II/README.md

@@ -1,28 +1,45 @@
 # [3333.Find the Original Typed String II][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
+Alice is attempting to type a specific string on her computer. However, she tends to be clumsy and **may** press a key for too long, resulting in a character being typed **multiple** times.
+
+You are given a string `word`, which represents the **final** output displayed on Alice's screen. You are also given a **positive** integer `k`.
+
+Return the total number of possible original strings that Alice might have intended to type, if she was trying to type a string of size **at least** `k`.
+
+Since the answer may be very large, return it **modulo** `10^9 + 7`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: word = "aabbccdd", k = 7
+
+Output: 5
+
+Explanation:
+
+The possible strings are: "aabbccdd", "aabbccd", "aabbcdd", "aabccdd", and "abbccdd".
+```
+
+**Example 2:**
+
 ```
+Input: word = "aabbccdd", k = 8
 
-## 题意
-> ...
+Output: 1
 
-## 题解
+Explanation:
 
-### 思路1
-> ...
-Find the Original Typed String II
-```go
+The only possible string is "aabbccdd".
 ```
 
+**Example 3:**
+
+```
+Input: word = "aaabbb", k = 3
+
+Output: 8
+```
 
 ## 结语
 

leetcode/3301-3400/3333.Find-the-Original-Typed-String-II/Solution.go

@@ -1,5 +1,53 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+const mod = 1000000007
+
+func Solution(word string, k int) int {
+	n := len(word)
+	cnt := 1
+	var freq []int
+
+	for i := 1; i < n; i++ {
+		if word[i] == word[i-1] {
+			cnt++
+		} else {
+			freq = append(freq, cnt)
+			cnt = 1
+		}
+	}
+	freq = append(freq, cnt)
+
+	ans := 1
+	for _, o := range freq {
+		ans = ans * o % mod
+	}
+
+	if len(freq) >= k {
+		return ans
+	}
+
+	f := make([]int, k)
+	g := make([]int, k)
+	f[0] = 1
+	for i := range g {
+		g[i] = 1
+	}
+
+	for i := 0; i < len(freq); i++ {
+		f_new := make([]int, k)
+		for j := 1; j < k; j++ {
+			f_new[j] = g[j-1]
+			if j-freq[i]-1 >= 0 {
+				f_new[j] = (f_new[j] - g[j-freq[i]-1] + mod) % mod
+			}
+		}
+		g_new := make([]int, k)
+		g_new[0] = f_new[0]
+		for j := 1; j < k; j++ {
+			g_new[j] = (g_new[j-1] + f_new[j]) % mod
+		}
+		f, g = f_new, g_new
+	}
+
+	return (ans - g[k-1] + mod) % mod
 }

leetcode/3301-3400/3333.Find-the-Original-Typed-String-II/Solution_test.go

@@ -10,30 +10,31 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs string
+		k      int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "aabbccdd", 7, 5},
+		{"TestCase2", "aabbccdd", 8, 1},
+		{"TestCase3", "aaabbb", 3, 8},
 	}
 
 	//	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.inputs, c.k)
 			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.inputs, c.k)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }