<p>Given a string <code>s</code>, return <em>the number of <strong>palindromic substrings</strong> in it</em>.</p>

<p>A string is a <strong>palindrome</strong> when it reads the same backward as forward.</p>

<p>A <strong>substring</strong> is a contiguous sequence of characters within the string.</p>

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

<pre>
<strong>Input:</strong> s = &quot;abc&quot;
<strong>Output:</strong> 3
<strong>Explanation:</strong> Three palindromic strings: &quot;a&quot;, &quot;b&quot;, &quot;c&quot;.
</pre>

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

<pre>
<strong>Input:</strong> s = &quot;aaa&quot;
<strong>Output:</strong> 6
<strong>Explanation:</strong> Six palindromic strings: &quot;a&quot;, &quot;a&quot;, &quot;a&quot;, &quot;aa&quot;, &quot;aa&quot;, &quot;aaa&quot;.
</pre>

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

<ul>
	<li><code>1 &lt;= s.length &lt;= 1000</code></li>
	<li><code>s</code> consists of lowercase English letters.</li>
</ul>

class Solution {
public:
int expand(string s,int i,int j)
{
    if(i<0||j>=s.size())
    return 0;
    else
    {
        if(s[i]==s[j])
        return 1+expand(s,i-1,j+1);
        else
        return 0;
    }
}
    int countSubstrings(string s) {
        int count=0;
        int i=0;
        for(i=0;i<s.size();i++)
        {
            count+=(1+expand(s,i-1,i+1));
            if(i<(s.size()-1)&&s[i]==s[i+1])
            {
                count+=(1+expand(s,i-1,i+2));
            }
        }
        return count;
    }
};
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