<p>Given a string <code>num</code> that contains only digits and an integer <code>target</code>, return <em><strong>all possibilities</strong> to insert the binary operators </em><code>&#39;+&#39;</code><em>, </em><code>&#39;-&#39;</code><em>, and/or </em><code>&#39;*&#39;</code><em> between the digits of </em><code>num</code><em> so that the resultant expression evaluates to the </em><code>target</code><em> value</em>.</p>

<p>Note that operands in the returned expressions <strong>should not</strong> contain leading zeros.</p>

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

<pre>
<strong>Input:</strong> num = &quot;123&quot;, target = 6
<strong>Output:</strong> [&quot;1*2*3&quot;,&quot;1+2+3&quot;]
<strong>Explanation:</strong> Both &quot;1*2*3&quot; and &quot;1+2+3&quot; evaluate to 6.
</pre>

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

<pre>
<strong>Input:</strong> num = &quot;232&quot;, target = 8
<strong>Output:</strong> [&quot;2*3+2&quot;,&quot;2+3*2&quot;]
<strong>Explanation:</strong> Both &quot;2*3+2&quot; and &quot;2+3*2&quot; evaluate to 8.
</pre>

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

<pre>
<strong>Input:</strong> num = &quot;3456237490&quot;, target = 9191
<strong>Output:</strong> []
<strong>Explanation:</strong> There are no expressions that can be created from &quot;3456237490&quot; to evaluate to 9191.
</pre>

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

<ul>
	<li><code>1 &lt;= num.length &lt;= 10</code></li>
	<li><code>num</code> consists of only digits.</li>
	<li><code>-2<sup>31</sup> &lt;= target &lt;= 2<sup>31</sup> - 1</code></li>
</ul>

class Solution {
public:

vector<string> func(int i, long long cursum, long long curr, long long tar, string s)
{
    string p;
    int n = s.size();
    vector<string>ans;
    long long d = 0;
    if(i == n)
    {
        if(cursum == tar)
        {
            return {{""}};
        }
        else
        {
            return {};
        }
    }
    for(int j=i;j<n;j++)
    {
        p += s[j];
        d = d*10 + (s[j]-'0');
        if(p.size() > 1 && p[0] == '0')
        {
            break;
        }
        if(i == 0)
        {
            for(auto val:func(j+1, d, d, tar, s))
            {
                ans.push_back(p+val);
            }
            continue;
        }
        for(auto val:func(j+1, cursum-d, -d, tar, s))
        {
            ans.push_back('-'+p+val);
        }
        for(auto val:func(j+1, cursum+d, d, tar, s))
        {
            ans.push_back('+'+p +val);
        }
        for(auto val:func(j+1, cursum-curr + d*curr, d*curr, tar, s))
        {
            ans.push_back('*' +p+ val);
        }
    }
    return ans;
}

    vector<string> addOperators(string s, int tar) {
        return func(0, 0, 0, tar, s);
    }
};
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