<p>Given two strings <code>a</code> and <code>b</code>, return <em>the minimum number of times you should repeat string </em><code>a</code><em> so that string</em> <code>b</code> <em>is a substring of it</em>. If it is impossible for <code>b</code>​​​​​​ to be a substring of <code>a</code> after repeating it, return <code>-1</code>.</p>

<p><strong>Notice:</strong> string <code>&quot;abc&quot;</code> repeated 0 times is <code>&quot;&quot;</code>, repeated 1 time is <code>&quot;abc&quot;</code> and repeated 2 times is <code>&quot;abcabc&quot;</code>.</p>

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

<pre>
<strong>Input:</strong> a = &quot;abcd&quot;, b = &quot;cdabcdab&quot;
<strong>Output:</strong> 3
<strong>Explanation:</strong> We return 3 because by repeating a three times &quot;ab<strong>cdabcdab</strong>cd&quot;, b is a substring of it.
</pre>

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

<pre>
<strong>Input:</strong> a = &quot;a&quot;, b = &quot;aa&quot;
<strong>Output:</strong> 2
</pre>

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

<ul>
	<li><code>1 &lt;= a.length, b.length &lt;= 10<sup>4</sup></code></li>
	<li><code>a</code> and <code>b</code> consist of lowercase English letters.</li>
</ul>

class Solution {
private:
int l = 0, r = 1e4 + 9;
string repeat(string in, int repeatTimes) {
    string out = "", temp = in;
    
    while(repeatTimes) {
        if(repeatTimes & 1) {
            out += temp;
        }
        temp = temp + temp;
        repeatTimes >>= 1;
    }

    return out;
}

int getNewBSearchValue() {
    return l + (r - l) / 2;
}

public:
    int repeatedStringMatch(string a, string b) {
        int n = a.length();
        r = r - n;
        if(r < 0) r = 1;
        int res = -1;
        while(l < r) {
            cout << l << " " << r <<endl; 
            int timesToRepeat = getNewBSearchValue();
            string aRepeated = repeat(a, timesToRepeat);
            if(aRepeated.find(b) != string::npos){
                res = timesToRepeat;
                r = timesToRepeat;
            } else {
                l = timesToRepeat + 1;
            }
        }
        return res;
    }
};
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