<p>Given an integer <code>n</code>, return <em>the least number of perfect square numbers that sum to</em> <code>n</code>.</p>

<p>A <strong>perfect square</strong> is an integer that is the square of an integer; in other words, it is the product of some integer with itself. For example, <code>1</code>, <code>4</code>, <code>9</code>, and <code>16</code> are perfect squares while <code>3</code> and <code>11</code> are not.</p>

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

<pre>
<strong>Input:</strong> n = 12
<strong>Output:</strong> 3
<strong>Explanation:</strong> 12 = 4 + 4 + 4.
</pre>

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

<pre>
<strong>Input:</strong> n = 13
<strong>Output:</strong> 2
<strong>Explanation:</strong> 13 = 4 + 9.
</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:
    long long dp[101][10001];
    long long func(int n,long long i,long long sum)
    {   
        if(i*i>n){
            return 1e9;
        }
        if(sum==n)
        {
            return 0;
        }
        
        if(dp[i][sum]!=-1)return dp[i][sum];
        long long op1=1e9;
        if(sum+i*i<=n){
          op1=1+func(n,i,sum+i*i);
        }
        long long op2=func(n,i+1,sum);
        return dp[i][sum]=min(op1,op2);
    }
    int numSquares(int n) {
        memset(dp,-1,sizeof(dp));
        return func(n,1,0);
    }
};
18180