<p>Given a string <code>expression</code> of numbers and operators, return <em>all possible results from computing all the different possible ways to group numbers and operators</em>. You may return the answer in <strong>any order</strong>.</p>

<p>The test cases are generated such that the output values fit in a 32-bit integer and the number of different results does not exceed <code>10<sup>4</sup></code>.</p>

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

<pre>
<strong>Input:</strong> expression = &quot;2-1-1&quot;
<strong>Output:</strong> [0,2]
<strong>Explanation:</strong>
((2-1)-1) = 0 
(2-(1-1)) = 2
</pre>

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

<pre>
<strong>Input:</strong> expression = &quot;2*3-4*5&quot;
<strong>Output:</strong> [-34,-14,-10,-10,10]
<strong>Explanation:</strong>
(2*(3-(4*5))) = -34 
((2*3)-(4*5)) = -14 
((2*(3-4))*5) = -10 
(2*((3-4)*5)) = -10 
(((2*3)-4)*5) = 10
</pre>

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

<ul>
	<li><code>1 &lt;= expression.length &lt;= 20</code></li>
	<li><code>expression</code> consists of digits and the operator <code>&#39;+&#39;</code>, <code>&#39;-&#39;</code>, and <code>&#39;*&#39;</code>.</li>
	<li>All the integer values in the input expression are in the range <code>[0, 99]</code>.</li>
</ul>

class Solution {
public:
    vector<int> diffWaysToCompute(string e) 
    {
        vector<int>results;
        if(e.size()==0)return results;
        if(e.size()==1)
        {
            results.push_back(e[0]-'0');
            return results;
        }
        if(e.size()==2 && isdigit(e[0]))
        {
            results.push_back(stoi(e));
            return results;
        }

        for(int i=0;i<e.size();i++)
        {
            char curr = e[i];
            if(isdigit(curr))continue;

            vector<int>leftres = diffWaysToCompute(e.substr(0,i));
            vector<int>rightres = diffWaysToCompute(e.substr(i+1));

            for(int l:leftres)
            {
                for(int r:rightres)
                {
                    int comp=0;
                    switch(curr)
                    {
                        case '+' :
                            comp = l+r;
                            break;
                        case '-' :
                            comp = l-r;
                            break;
                        case '*' :
                            comp = l*r;
                            break;
                    }
                    results.push_back(comp);
                }
            }
        }
        return results;
    }
};
13000