Merge pull request #1366 from 0xff-dev/3271

Add solution and test-cases for problem 3271

Author: 6boris

leetcode/3201-3300/3271.Hash-Divided-String/README.md

@@ -1,28 +1,45 @@
 # [3271.Hash Divided String][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 a string `s` of length `n` and an integer `k`, where `n` is a **multiple** of `k`. Your task is to hash the string `s` into a new string called `result`, which has a length of `n / k`.
+
+First, divide `s` into `n / k` substrings, each with a length of `k`. Then, initialize `result` as an **empty** string.
+
+For each **substring** in order from the beginning:
+
+- The **hash value** of a character is the index of that character in the **English alphabet** (e.g., `'a' → 0, 'b' → 1, ..., 'z' → 25`).
+- Calculate the sum of all the **hash values** of the characters in the substring.
+- Find the remainder of this sum when divided by 26, which is called `hashedChar`.
+- Identify the character in the English lowercase alphabet that corresponds to `hashedChar`.
+- Append that character to the end of `result`.
+
+Return `result`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
-```
+Input: s = "abcd", k = 2
+
+Output: "bf"
 
-## 题意
-> ...
+Explanation:
 
-## 题解
+First substring: "ab", 0 + 1 = 1, 1 % 26 = 1, result[0] = 'b'.
 
-### 思路1
-> ...
-Hash Divided String
-```go
+Second substring: "cd", 2 + 3 = 5, 5 % 26 = 5, result[1] = 'f'.
 ```
 
+**Example 2:**
+
+```
+Input: s = "mxz", k = 3
+
+Output: "i"
+
+Explanation:
+
+The only substring: "mxz", 12 + 23 + 25 = 60, 60 % 26 = 8, result[0] = 'i'.
+```
 
 ## 结语
 

leetcode/3201-3300/3271.Hash-Divided-String/Solution.go

@@ -1,5 +1,18 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import "bytes"
+
+func Solution(s string, k int) string {
+	buf := bytes.NewBuffer([]byte{})
+	sum := 0
+	for i := 0; i < len(s); i++ {
+		if i != 0 && i%k == 0 {
+			buf.WriteByte(byte(sum%26 + 'a'))
+			sum = int(s[i]-'a')
+			continue
+		}
+		sum += int(s[i] - 'a')
+	}
+	buf.WriteByte(byte(sum%26 + 'a'))
+	return buf.String()
 }

leetcode/3201-3300/3271.Hash-Divided-String/Solution_test.go

@@ -10,30 +10,30 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs string
+		k      int
+		expect string
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "abcd", 2, "bf"},
+		{"TestCase2", "mxz", 3, "i"},
 	}
 
 	//	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() {
 }