Add solution and test-cases for problem 3043

leetcode/3001-3100/3043.Find-the-Length-of-the-Longest-Common-Prefix/README.md

@@ -1,28 +1,36 @@
 # [3043.Find the Length of the Longest Common Prefix][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 arrays with **positive** integers `arr1` and `arr2`.
+
+A **prefix** of a positive integer is an integer formed by one or more of its digits, starting from its **leftmost** digit. For example, `123` is a prefix of the integer `12345`, while `234` is **not**.
+
+A **common prefix** of two integers `a` and `b` is an integer `c`, such that `c` is a prefix of both `a` and `b`. For example, `5655359` and `56554` have a common prefix `565` while `1223` and `43456` do not have a common prefix.
+
+You need to find the length of the **longest common prefix** between all pairs of integers `(x, y)` such that `x` belongs to `arr1` and `y` belongs to `arr2`.
+
+Return the length of the **longest** common prefix among all pairs. If no common prefix exists among them, return `0`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: arr1 = [1,10,100], arr2 = [1000]
+Output: 3
+Explanation: There are 3 pairs (arr1[i], arr2[j]):
+- The longest common prefix of (1, 1000) is 1.
+- The longest common prefix of (10, 1000) is 10.
+- The longest common prefix of (100, 1000) is 100.
+The longest common prefix is 100 with a length of 3.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Find the Length of the Longest Common Prefix
-```go
 ```
-
+Input: arr1 = [1,2,3], arr2 = [4,4,4]
+Output: 0
+Explanation: There exists no common prefix for any pair (arr1[i], arr2[j]), hence we return 0.
+Note that common prefixes between elements of the same array do not count.
+```
 
 ## 结语
 

leetcode/3001-3100/3043.Find-the-Length-of-the-Longest-Common-Prefix/Solution.go

@@ -1,5 +1,47 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import (
+	"strconv"
+)
+
+type trieNode3043 struct {
+	child [10]*trieNode3043
+}
+
+func (r *trieNode3043) insert(intStr string) {
+	walker := r
+	for i := range intStr {
+		index := intStr[i] - '0'
+		if walker.child[index] == nil {
+			walker.child[index] = &trieNode3043{child: [10]*trieNode3043{}}
+		}
+		walker = walker.child[index]
+	}
+}
+
+func (r *trieNode3043) prefixMatch(intStr string) int {
+	walker := r
+	i := 0
+	for ; i < len(intStr); i++ {
+		index := intStr[i] - '0'
+		if walker.child[index] == nil {
+			break
+		}
+		walker = walker.child[index]
+	}
+	return i
+}
+
+func Solution(arr1 []int, arr2 []int) int {
+	ans := 0
+	tree := &trieNode3043{}
+	for _, intVal := range arr1 {
+		v := strconv.Itoa(intVal)
+		tree.insert(v)
+	}
+	for _, intVal := range arr2 {
+		v := strconv.Itoa(intVal)
+		ans = max(ans, tree.prefixMatch(v))
+	}
+	return ans
 }

leetcode/3001-3100/3043.Find-the-Length-of-the-Longest-Common-Prefix/Solution_test.go

@@ -10,30 +10,29 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		a1, a2 []int
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{1, 10, 100}, []int{1000}, 3},
+		{"TestCase2", []int{1, 2, 3}, []int{4, 4, 4}, 0},
 	}
 
 	//	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.a1, c.a2)
 			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.a1, c.a2)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }