面试题3：数组中重复的数字

class Solution {
public:
    // Parameters:
    //        numbers:     an array of integers
    //        length:      the length of array numbers
    //        duplication: (Output) the duplicated number in the array number
    // Return value:       true if the input is valid, and there are some duplications in the array number
    //                     otherwise false
    bool duplicate(int numbers[], int length, int* duplication) {
        if (numbers == nullptr || length <= 0)
        {
            return false;
        }
        for (int i = 0; i < length; ++i)
        {
            if (numbers[i]<0 || numbers[i]>length - 1)
            {
                return false;
            }

            while (numbers[i] != i)
            {
                if (numbers[i] == numbers[numbers[i]])
                {
                    *duplication = numbers[i];
                    return true;
                }
                int temp = numbers[i];
                numbers[i] = numbers[temp];
                numbers[temp] = temp;
            }
        }

        return false;
    }
};