<p>An integer <code>x</code> is a <strong>good</strong> if after rotating each digit individually by 180 degrees, we get a valid number that is different from <code>x</code>. Each digit must be rotated - we cannot choose to leave it alone.</p>

<p>A number is valid if each digit remains a digit after rotation. For example:</p>

<ul>
	<li><code>0</code>, <code>1</code>, and <code>8</code> rotate to themselves,</li>
	<li><code>2</code> and <code>5</code> rotate to each other (in this case they are rotated in a different direction, in other words, <code>2</code> or <code>5</code> gets mirrored),</li>
	<li><code>6</code> and <code>9</code> rotate to each other, and</li>
	<li>the rest of the numbers do not rotate to any other number and become invalid.</li>
</ul>

<p>Given an integer <code>n</code>, return <em>the number of <strong>good</strong> integers in the range </em><code>[1, n]</code>.</p>

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

<pre>
<strong>Input:</strong> n = 10
<strong>Output:</strong> 4
<strong>Explanation:</strong> There are four good numbers in the range [1, 10] : 2, 5, 6, 9.
Note that 1 and 10 are not good numbers, since they remain unchanged after rotating.
</pre>

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

<pre>
<strong>Input:</strong> n = 1
<strong>Output:</strong> 0
</pre>

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

<pre>
<strong>Input:</strong> n = 2
<strong>Output:</strong> 1
</pre>

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

<ul>
	<li><code>1 &lt;= n &lt;= 10<sup>4</sup></code></li>
</ul>

class Solution {
public:
    vector<int> rotate;

    bool solve(int n){
        int num = n;
        vector<int> v;
        while(num!=0) {
            int r = num%10;
            num = num/10;
            v.push_back(r);
        }

        for(int i=0; i<v.size(); i++){
            v[i] = rotate[v[i]];
        }

        int ans = 0;

        for(int i=v.size()-1; i>=0; i--){
            if(v[i]==-1){
                return false;
            }
            ans = ans*10 + v[i];
        }
        return ans!=n;
    }

    int rotatedDigits(int n) { 
        rotate.resize(10);       
        rotate[0] = 0;
        rotate[1] = 1;
        rotate[2] = 5;
        rotate[3] = -1;
        rotate[4] = -1;
        rotate[5] = 2;
        rotate[6] = 9;
        rotate[7] = -1;
        rotate[8] = 8;
        rotate[9] = 6;

        int ans = 0;

        for(int i=1;i<=n;i++){
            if(solve(i)){
                ans++;
            }
        }

        return ans;
    }
};
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