<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:
    
    int validate(int n,map<int,char>&mirror){
        int k=n;
        string s="";
        while(n>0){
            int rem=n%10;
            if(mirror.find(rem)==mirror.end())return -1;
            s=mirror[rem]+s;
            n=n/10;
        }
        int num=stoi(s);
        if(num==k) return -1;
        return num;
    }
    int rotatedDigits(int n) {
        int k=1;
        map<int,char>mirror;
        mirror[2]='5';
        mirror[5]='2';
        mirror[6]='9';
        mirror[9]='6';
        mirror[0]='0';
        mirror[1]='1';
        mirror[8]='8';
        map<int,int>mp;
        for(int i=1;i<=n;i++){
            if(mp.find(i)==mp.end()){
                int val=validate(i,mirror);
                if(val!=-1){
                    //cout<<(k++)<<" : "<<i<<" "<<val<<endl;
                    mp[i]=1;
                    if(val<=n) mp[val]=1;
                }
            }
        }
        return mp.size();
    }
};
13600