minlen of expression of integer

given an integer ，find 最小长度minlen 的expression of integer， minlen 定义为多少个完全平方数相加
例如 14 = 1 + 4 + 9， minlen = 3

int MinExpressionInteger(int i)
{
    int k = sqrt(i);
    if (k*k == i)
        return 1;
    int minLen = INT_MAX;
    while (k > sqrt(i / 2) - 1)
    {
        int len = 1 + MinExpressionInteger(i - k*k);
        if (minLen > len)
            minLen = len;
        k--;
    }
    return minLen;
}