<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) {
        vector<long long> v;
        long end=ceil(sqrt(c));
        cout<<end<<endl;
        for(long i=0;i<=end;i++){
            v.push_back(i*i);
            //cout<<i*i<<" ";

        }
        int l=0,r=v.size()-1;
        while(l<=r){
            long long sum=v[l]+v[r];
            if(sum==c){
               // cout<<"true";
                return true;

            }
            else if(sum>c){
               // cout<<"r--";
                r--;
            }
            else {
                //cout<<"l++";
                l++;

            }

        }
        return false;
    }
};
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