<p>Given a string <code>s</code>, return <code>true</code> <em>if the </em><code>s</code><em> can be palindrome after deleting <strong>at most one</strong> character from it</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;aba&quot;
<strong>Output:</strong> true
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;abca&quot;
<strong>Output:</strong> true
<strong>Explanation:</strong> You could delete the character &#39;c&#39;.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;abc&quot;
<strong>Output:</strong> false
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 10<sup>5</sup></code></li>
	<li><code>s</code> consists of lowercase English letters.</li>
</ul>

class Solution {
public:
    // abca

    bool validPalindrome(const string& s) {
        int start = 0, end = s.length()-1;
        while (start < end) {
            if (s[start] != s[end]) {
                return checkPalindrome(s, start, end-1) ||
                    checkPalindrome(s, start+1, end);
            }

            start++;
            end--;
        }

        return true;
    }

private:
    bool checkPalindrome(const string& s, int start, int end) {
        while (start < end) {
            if (s[start] != s[end]) return false;

            start++;
            end--;
        }

        return true;
    }
};
17823