Add solution and test-cases for problem 848

Author: 0xff-dev

leetcode/801-900/0848.Shifting-Letters/README.md

@@ -1,28 +1,33 @@
 # [848.Shifting Letters][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 lowercase English letters and an integer array `shifts` of the same length.
+
+Call the `shift()` of a letter, the next letter in the alphabet, (wrapping around so that `'z'` becomes `'a'`).
+
+- For example, `shift('a') = 'b'`, `shift('t') = 'u'`, and `shift('z') = 'a'`.
+
+Now for each `shifts[i] = x`, we want to shift the first `i + 1` letters of `s`, x times.
+
+Return the final string after all such shifts to s are applied.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: s = "abc", shifts = [3,5,9]
+Output: "rpl"
+Explanation: We start with "abc".
+After shifting the first 1 letters of s by 3, we have "dbc".
+After shifting the first 2 letters of s by 5, we have "igc".
+After shifting the first 3 letters of s by 9, we have "rpl", the answer.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Shifting Letters
-```go
 ```
-
+Input: s = "aaa", shifts = [1,2,3]
+Output: "gfd"
+```
 
 ## 结语
 

leetcode/801-900/0848.Shifting-Letters/Solution.go

@@ -1,5 +1,12 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(s string, shifts []int) string {
+	ans := []byte(s)
+	sum := 0
+	for i := len(s) - 1; i >= 0; i-- {
+		sum += shifts[i]
+		now := (int(ans[i]-'a') + sum) % 26
+		ans[i] = byte(now) + 'a'
+	}
+	return string(ans)
 }

leetcode/801-900/0848.Shifting-Letters/Solution_test.go

@@ -10,18 +10,18 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs string
+		shifts []int
+		expect string
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "abc", []int{3, 5, 9}, "rpl"},
+		{"TestCase2", "aaa", []int{1, 2, 3}, "gfd"},
 	}
 
 	//	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.shifts)
 			if !reflect.DeepEqual(got, c.expect) {
 				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
 					c.expect, got, c.inputs)
@@ -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() {
 }