数组中重复的数字

bool duplicate(int numbers[], int length, int* duplication) {
        if (numbers == nullptr || length <= 0){
            return false;
        }
        for (int i = 0; i < length; i++){
            while(numbers[i] != i){
                int temp = numbers[i];
                if (numbers[i] == numbers[temp]){
                    *duplication = numbers[i];
                    return true;
                }
                    numbers[i] = numbers[temp];
                    numbers[temp] = temp;
            }
        }
        return false;
    }
};