<p>Given a non-negative integer <code>c</code>, decide whether there&#39;re two integers <code>a</code> and <code>b</code> such that <code>a<sup>2</sup> + b<sup>2</sup> = c</code>.</p>

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

<pre>
<strong>Input:</strong> c = 5
<strong>Output:</strong> true
<strong>Explanation:</strong> 1 * 1 + 2 * 2 = 5
</pre>

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

<pre>
<strong>Input:</strong> c = 3
<strong>Output:</strong> false
</pre>

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

<ul>
	<li><code>0 &lt;= c &lt;= 2<sup>31</sup> - 1</code></li>
</ul>

class Solution {
public:
    bool judgeSquareSum(int c) {
        if(c<2){
            return true;
        }
        int a=sqrt(c);
        vector<int>ans;
       
        while(a!=0){
            ans.push_back(a);
            a--;


        }
        ans.push_back(0);
        
        for(int i=0;i<ans.size();i++){
            ans[i]=pow(ans[i],2);
        }
        unordered_map<int,int>m;
        for(int i=0;i<ans.size();i++){
           m[ans[i]]++;
           int comp=c-ans[i];
           if(m.find(comp)!=m.end()){
            return true;
           }
        }
        return false;

       




        
    }
};
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