Merge pull request #1188 from 0xff-dev/125

Add solution and test-cases for problem 125

Author: 6boris

leetcode/101-200/0125.Valid-Palindrome/README.md

@@ -0,0 +1,38 @@
+# [125.Valid Palindrome][title]
+
+## Description
+A phrase is a **palindrome** if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers.
+
+Given a string `s`, return `true` if it is a **palindrome**, or `false` otherwise.
+
+**Example 1:**
+
+```
+Input: s = "A man, a plan, a canal: Panama"
+Output: true
+Explanation: "amanaplanacanalpanama" is a palindrome.
+```
+
+**Example 2:**
+
+```
+Input: s = "race a car"
+Output: false
+Explanation: "raceacar" is not a palindrome.
+```
+
+**Example 3:**
+
+```
+Input: s = " "
+Output: true
+Explanation: s is an empty string "" after removing non-alphanumeric characters.
+Since an empty string reads the same forward and backward, it is a palindrome.
+```
+
+## 结语
+
+如果你同我一样热爱数据结构、算法、LeetCode，可以关注我 GitHub 上的 LeetCode 题解：[awesome-golang-algorithm][me]
+
+[title]: https://leetcode.com/problems/valid-palindrome
+[me]: https://github.com/kylesliu/awesome-golang-algorithm

leetcode/101-200/0125.Valid-Palindrome/Solution.go

@@ -1,5 +1,40 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(s string) bool {
+	var is func(byte) byte
+	is = func(b byte) byte {
+		if b >= '0' && b <= '9' {
+			return b
+		}
+		if b >= 'a' && b <= 'z' {
+			return b
+		}
+		if b >= 'A' && b <= 'Z' {
+			return b + 32
+		}
+		return byte(' ')
+	}
+	l, r := 0, len(s)-1
+	var bl, br byte
+	for l < r {
+		for ; l < r; l++ {
+			bl = is(s[l])
+			if bl != byte(' ') {
+				break
+			}
+		}
+		for ; l < r; r-- {
+			br = is(s[r])
+			if br != byte(' ') {
+				break
+			}
+		}
+		if l < r {
+			if bl != br {
+				return false
+			}
+			l, r = l+1, r-1
+		}
+	}
+	return true
 }

leetcode/101-200/0125.Valid-Palindrome/Solution_test.go

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
+		inputs string
 		expect bool
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "A man, a plan, a canal: Panama", true},
+		{"TestCase2", "race a car", false},
+		{"TestCase3", " ", true},
 	}
 
 	//	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() {
 }