some more neetcode

125-valid-palindrome/driver.cpp

@@ -0,0 +1,10 @@
+#include "soln.hpp"
+
+int main()
+{
+	string s = "A man, a plan, a canal: Panama";
+	bool answer = true;
+	Solution soln;
+	cout << "Checked palindrome correctly? " << soln.test(s, answer) << endl;
+	return 0;
+}

125-valid-palindrome/soln.cpp

@@ -0,0 +1,32 @@
+#include "soln.hpp"
+
+bool Solution::isPalindrome(string s)
+{
+	int n = s.length();
+	if (n < 2)
+		return true;
+	for (int i = 0; i < n; i++)
+	{
+		if (s[i] >= 'A' && s[i] <= 'Z')
+			s[i] += 32;
+		if ((s[i] < 'a' || s[i] > 'z') &&
+			(s[i] < '0' || s[i] > '9'))
+		{
+			s.erase(s.begin() + i);
+			i--;
+			n--;
+		}
+	}
+	n = s.length();
+	for (int i = 0, j = n - 1; i < n / 2; i++, j--)
+	{
+		if (s[i] != s[n - i - 1])
+			return false;
+	}
+	return true;
+}
+
+bool Solution::test(string s, bool answer)
+{
+	return isPalindrome(s) == answer;
+}

125-valid-palindrome/soln.hpp

@@ -0,0 +1,8 @@
+#include <bits/stdc++.h>
+using namespace std;
+class Solution
+{
+public:
+	bool isPalindrome(string s);
+	bool test(string s, bool answer);
+};