LeetCode_Algorithms_217_Contains_Duplicate_Impl1.cs

public bool ContainsDuplicate(int[] nums)
{
    int count = nums.Count();
    if (count == 0) return false;
    int max = nums.Max();
    int min = nums.Min();
    int[] positiveRecord = new int[max + 1];
    int[] negativeRecord = new int[(min < 0) ? Math.Abs(min) + 1 : 0];
    for (int i = 0; i < count; i++)
    {
        if (nums[i] >= 0)
        {
            if (positiveRecord[nums[i]] == 1)
                return true;
            else
                positiveRecord[nums[i]] = 1;
        }
        else
        {
            if (negativeRecord[nums[i] * -1] == 1)
                return true;
            else
                negativeRecord[nums[i] * -1] = 1;
        }
    }
    return false;
}