问题

Complete the following python code:

def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.

Examples
is_sorted([5]) ➞ True
is_sorted([1, 2, 3, 4, 5]) ➞ True
is_sorted([1, 3, 2, 4, 5]) ➞ False
is_sorted([1, 2, 3, 4, 5, 6]) ➞ True
is_sorted([1, 2, 3, 4, 5, 6, 7]) ➞ True
is_sorted([1, 3, 2, 4, 5, 6, 7]) ➞ False
is_sorted([1, 2, 2, 3, 3, 4]) ➞ True
is_sorted([1, 2, 2, 2, 3, 4]) ➞ False
'''

答案

模型 模型答案 测试结果
金声玉亮2.0 Certainly! Here's the complete implementation of the `is_sorted` function:

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.

Examples
is_sorted([5]) ➞ True
is_sorted([1, 2, 3, 4, 5]) ➞ True
is_sorted([1, 3, 2, 4, 5]) ➞ False
is_sorted([1, 2, 3, 4, 5, 6]) ➞ True
is_sorted([1, 2, 3, 4, 5, 6, 7]) ➞ True
is_sorted([1, 3, 2, 4, 5, 6, 7]) ➞ False
is_sorted([1, 2, 2, 3, 3, 4]) ➞ True
is_sorted([1, 2, 2, 2, 3, 4]) ➞ False
'''
# Check if the list is sorted in ascending order
if lst != sorted(lst):
return False

# Check for duplicates
from collections import Counter
count = Counter(lst)
if any(value > 2 for value in count.values()):
return False

return True

# Test cases
print(is_sorted([5])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5])) # ➞ False
print(is_sorted([1, 2, 3, 4, 5, 6])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # ➞ False
print(is_sorted([1, 2, 2, 3, 3, 4])) # ➞ True
print(is_sorted([1, 2, 2, 2, 3, 4])) # ➞ False
```

This function first checks if the list is sorted in ascending order by comparing it to its sorted version. Then, it checks for duplicates using the `Counter` from the `collections` module. If any number appears more than twice, it returns `False`. Otherwise, it returns `True`.
passed
deepseekr1

To solve this problem, we need to determine if a given list of integers is sorted in ascending order and ensure that no number appears more than twice. The solution involves two main checks: verifying the list's order and validating the frequency of each element.

### Approach
1. **Check if the List is Sorted**: Iterate through the list and compare each element with the next one. If any element is found to be greater than the next, the list is not sorted in ascending order.
2. **Check Element Frequency**: Use a dictionary to count occurrences of each element in the list. If any element appears more than twice, the list does not meet the criteria.

### Solution Code
```python
def is_sorted(lst):
# Check if the list is sorted in ascending order
for i in range(len(lst) - 1):
if lst[i] > lst[i + 1]:
return False

# Check if any number appears more than twice
counts = {}
for num in lst:
counts[num] = counts.get(num, 0) + 1
if counts[num] > 2:
return False

return True
```

### Explanation
1. **Sorted Check**: The loop iterates through the list, comparing each element with the next. If any element is greater than the next, the function immediately returns `False`.
2. **Frequency Check**: A dictionary is used to count occurrences of each element. If any element's count exceeds 2, the function returns `False`.

This approach ensures both conditions are checked efficiently. The time complexity is O(n), where n is the number of elements in the list, as we iterate through the list twice—once for the sorted check and once for the frequency check. The space complexity is O(n) due to the dictionary used for counting frequencies.
passed
gpto1 To meet the requirements specified in the problem description, we'll create a function `is_sorted(lst)` that will perform two main checks:

1. **Sorted Order Check**: Verify that the list is sorted in ascending order. This means each element should be less than or equal to the next element.
2. **Duplicate Count Check**: Ensure that no number appears more than twice in the list.

Since the list is assumed to be of non-negative integers and possibly contains duplicates, we need an efficient way to count duplicates without using extra space for storing counts, especially since the list may be large.

Here's the implementation:

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.
'''
# Check if the list is sorted in ascending order
for i in range(len(lst)-1):
if lst[i] > lst[i+1]:
return False

# Check that no number appears more than twice
count = 1 # Initialize count for the first element
for i in range(1, len(lst)):
if lst[i] == lst[i-1]:
count += 1
if count > 2:
return False # More than two duplicates found
else:
count = 1 # Reset count for a new number

return True
```

**Explanation:**

- **Sorted Order Check**: The first `for` loop iterates through the list and checks if each element is less than or equal to the next. If it finds any element that is greater than the next one, it returns `False`.

- **Duplicate Count Check**: The second `for` loop, starting from the second element, checks if the current element is the same as the previous one. If it is, it increments the `count`. If the `count` exceeds 2, it means the number appears more than twice, and the function returns `False`. If the current element is different, it resets the `count` to 1.

**Test Cases:**

Let's test the function with the provided examples:

```python
print(is_sorted([5])) # Output: True
print(is_sorted([1, 2, 3, 4, 5])) # Output: True
print(is_sorted([1, 3, 2, 4, 5])) # Output: False
print(is_sorted([1, 2, 3, 4, 5, 6])) # Output: True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # Output: True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # Output: False
print(is_sorted([1, 2, 2, 3, 3, 4])) # Output: True
print(is_sorted([1, 2, 2, 2, 3, 4])) # Output: False
```

All the test cases should produce outputs as expected according to the problem description.
passed
GPT-4o To complete the Python function `is_sorted`, we'll need to check two conditions:
1. The list must be in ascending order.
2. The list must not have more than one duplicate of the same number.

Here's the complete implementation:

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.
'''
if not lst: # if the list is empty, consider it sorted
return True

# Check for ascending order and duplicates
count_dict = {}
for i in range(len(lst) - 1):
if lst[i] > lst[i + 1]:
return False
if lst[i] in count_dict:
count_dict[lst[i]] += 1
else:
count_dict[lst[i]] = 1

# Check for more than one duplicate
if count_dict[lst[i]] > 2:
return False

# Check the last element for duplicates
if lst[-1] in count_dict:
count_dict[lst[-1]] += 1
else:
count_dict[lst[-1]] = 1

if count_dict[lst[-1]] > 2:
return False

return True

# Test cases
print(is_sorted([5])) # True
print(is_sorted([1, 2, 3, 4, 5])) # True
print(is_sorted([1, 3, 2, 4, 5])) # False
print(is_sorted([1, 2, 3, 4, 5, 6])) # True
print(is_sorted([1, 2, 2, 3, 3, 4])) # True
print(is_sorted([1, 2, 2, 2, 3, 4])) # False
```

Explanation:
- The function iterates through the list, checking if each element is less than or equal to the next element. If not, it returns `False`.
- A dictionary `count_dict` is used to keep track of the occurrences of each number.
- If any number appears more than twice, the function returns `False`.
- The function returns `True` if the list is in ascending order and no
passed
llama3.1-70B-Instruct

def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.

Examples
is_sorted([5]) True
is_sorted([1, 2, 3, 4, 5]) True
is_sorted([1, 3, 2, 4, 5]) False
is_sorted([1, 2, 3, 4, 5, 6]) True
is_sorted([1, 2, 3, 4, 5, 6, 7]) True
is_sorted([1, 3, 2, 4, 5, 6, 7]) False
is_sorted([1, 2, 2, 3, 3, 4]) True
is_sorted([1, 2, 2, 2, 3, 4]) False
'''
# Check if the list is sorted in ascending order
if lst != sorted(lst):
return False

# Check if there are more than one duplicate of the same number
for num in lst:
if lst.count(num) > 2:
return False

return True
passed
llama3.1-405B-Instruct

Here is the completed Python code:

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.

Examples
is_sorted([5]) ➞ True
is_sorted([1, 2, 3, 4, 5]) ➞ True
is_sorted([1, 3, 2, 4, 5]) ➞ False
is_sorted([1, 2, 3, 4, 5, 6]) ➞ True
is_sorted([1, 2, 3, 4, 5, 6, 7]) ➞ True
is_sorted([1, 3, 2, 4, 5, 6, 7]) ➞
failed: unterminated triple-quoted string literal (detected at line 56) (<string>, line 24)
DeepSeek-Coder-V2 Here's the completed Python function `is_sorted` that checks if a list of integers is sorted in ascending order, considering the condition that if there are more than one duplicate of the same number, it should return `False`.

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.

Examples
is_sorted([5]) ➞ True
is_sorted([1, 2, 3, 4, 5]) ➞ True
is_sorted([1, 3, 2, 4, 5]) ➞ False
is_sorted([1, 2, 3, 4, 5, 6]) ➞ True
is_sorted([1, 2, 3, 4, 5, 6, 7]) ➞ True
is_sorted([1, 3, 2, 4, 5, 6, 7]) ➞ False
is_sorted([1, 2, 2, 3, 3, 4]) ➞ True
is_sorted([1, 2, 2, 2, 3, 4]) ➞ False
'''
# Check for duplicates more than 1
if len(lst) != len(set(lst)):
for num in set(lst):
if lst.count(num) > 1:
return False

# Check if the list is sorted in ascending order
return all(lst[i] <= lst[i+1] for i in range(len(lst)-1))

# Test cases
print(is_sorted([5])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5])) # ➞ False
print(is_sorted([1, 2, 3, 4, 5, 6])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # ➞ False
print(is_sorted([1, 2, 2, 3, 3, 4])) # ➞ True
print(is_sorted([1, 2, 2, 2, 3, 4])) # ➞ False
```

This function first checks for any number that appears more than once in the list. If such a number is found, it returns `False`. Then, it checks if the list is sorted in ascending order using a generator expression within the `all` function. If both conditions are satisfied, it returns `True`.
failed: This prints if this assert fails 7 (good for debugging!)
Qwen2-72B-Instruct Here is the solution:

```python
def is_sorted(lst):
# Check for sort order
if lst != sorted(lst):
return False

# Check for more than 1 duplicate of the same number
for num in lst:
if lst.count(num) > 2:
return False

return True
```

However, the above solution is not optimal as it will count the frequency of each number in the list for every number, which makes the time complexity of the function O(n^2). A better approach is to use the built-in Python function `collections.Counter()` to count the frequencies of the numbers in one pass, and then check if any number has a frequency more than 2. Here is the optimized solution:

```python
from collections import Counter

def is_sorted(lst):
# Check for sort order
if lst != sorted(lst):
return False

# Count the frequency of each number
count = Counter(lst)

# Check for more than 1 duplicate of the same number
if any(freq > 2 for freq in count.values()):
return False

return True
```
But the best solution is to combine the two checks into one, like this:

```python
from collections import Counter

def is_sorted(lst):
# Count the frequency of each number
count = Counter(lst)

# Check for sort order and more than 1 duplicate of the same number
last_num = None
for num, freq in count.items():
if last_num is not None and num <= last_num:
return False
if freq > 2:
return False
last_num = num

return True
```
passed
baichuan4 Here's the completed Python code for the `is_sorted` function:

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.

Examples
is_sorted([5]) ➞ True
is_sorted([1, 2, 3, 4, 5]) ➞ True
is_sorted([1, 3, 2, 4, 5]) ➞ False
is_sorted([1, 2, 3, 4, 5, 6]) ➞ True
is_sorted([1, 2, 3, 4, 5, 6, 7]) ➞ True
is_sorted([1, 3, 2, 4, 5, 6, 7]) ➞ False
is_sorted([1, 2, 2, 3, 3, 4]) ➞ True
is_sorted([1, 2, 2, 2, 3, 4]) ➞ False
'''
# Check if the list is empty or has only one element, which is trivially sorted
if len(lst) <= 1:
return True

# Check for more than one duplicate
unique_numbers = set()
for num in lst:
if num in unique_numbers:
return False
unique_numbers.add(num)

# Check if the list is sorted in ascending order
for i in range(len(lst) - 1):
if lst[i] > lst[i + 1]:
return False

return True

# Example usage:
print(is_sorted([5])) # True
print(is_sorted([1, 2, 3, 4, 5])) # True
print(is_sorted([1, 3, 2, 4, 5])) # False
print(is_sorted([1, 2, 3, 4, 5, 6])) # True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # False
print(is_sorted([1, 2, 2, 3, 3, 4])) # True
print(is_sorted([1, 2, 2, 2, 3, 4])) # False
```

This function first checks if the list is trivially sorted by being empty or having only one element. Then, it uses a set to keep track of unique numbers and immediately returns `False` if a duplicate is found. Finally, it iterates through the list to ensure each element is less than or equal to the next one, returning `False` if the order is broken, and `True` if the entire list is sorted without duplicates.
failed: This prints if this assert fails 7 (good for debugging!)
doubao Here's the completed Python code:

```python
def is_sorted(lst):
for i in range(len(lst) - 1):
if lst[i] > lst[i + 1] or (lst[i] == lst[i + 1] and lst.count(lst[i]) > 1):
return False
return True
```
failed: This prints if this assert fails 7 (good for debugging!)
minimax The description of the function `is_sorted` seems to have a contradiction. It states that if the list has more than one duplicate of the same number, the function should return `False`. However, the last example contradicts this by returning `True` for the list `[1, 2, 2, 3, 3, 4]`. Assuming that the function should return `False` for lists with more than one duplicate of the same number, here is the completed code:

```python
def is_sorted(lst):
# Check if the list has more than one duplicate of the same number
if len(lst) != len(set(lst)):
return False

# Check if the list is sorted in ascending order
for i in range(len(lst) - 1):
if lst[i] > lst[i + 1]:
return False

return True

# Examples
print(is_sorted([5])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5])) # ➞ False
print(is_sorted([1, 2, 3, 4, 5, 6])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # ➞ False
print(is_sorted([1, 2, 2, 3, 3, 4])) # ➞ False (assuming the description is correct)
print(is_sorted([1, 2, 2, 2, 3, 4])) # ➞ False
```

If the description is incorrect and the function should return `True` for lists with duplicates (as shown in the last example), then the code should be modified to remove the check for duplicates:

```python
def is_sorted(lst):
# Check if the list is sorted in ascending order
for i in range(len(lst) - 1):
if lst[i] > lst[i + 1]:
return False

return True

# Examples
print(is_sorted([5])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5])) # ➞ False
print(is_sorted([1, 2, 3, 4, 5, 6])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # ➞ False
print(is_sorted([1, 2, 2, 3, 3, 4])) # ➞ True (assuming the last example is correct)
print(is_sorted([1, 2, 2, 2, 3, 4])) # ➞ False
```

Please clarify the correct behavior for lists with duplicates if the examples provided are not accurate.
failed: This prints if this assert fails 7 (good for debugging!)
kimi Here's the completed Python code for the function `is_sorted`:

```python
def is_sorted(lst):
# Check if the list is sorted in ascending order
# and if there are no more than one duplicate of the same number
for i in range(len(lst) - 1):
if lst[i] >= lst[i + 1]:
return False
if lst[i] == lst[i + 1]:
if lst.count(lst[i]) > 2:
return False
return True

# Examples
print(is_sorted([5])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5])) # ➞ False
print(is_sorted([1, 2, 3, 4, 5, 6])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # ➞ False
print(is_sorted([1, 2, 2, 3, 3, 4])) # ➞ True
print(is_sorted([1, 2, 2, 2, 3, 4])) # ➞ False
```

This function iterates through the list and checks if each element is less than or equal to the next one, which would mean the list is not sorted in ascending order. It also checks if any number is duplicated more than twice, which would also result in `False`. If none of these conditions are met, the function returns `True`.
failed: This prints if this assert fails 7 (good for debugging!)
wenxinyiyan Here's the completed Python code for the `is_sorted` function:


```python
def is_sorted(lst):
if len(lst) <= 1:
return True

prev_num = lst[0]
prev_count = 1

for i in range(1, len(lst)):
if lst[i] == prev_num:
prev_count += 1
if prev_count > 2:
return False
elif lst[i] < prev_num:
return False
else:
prev_num = lst[i]
prev_count = 1

return True
```
Explanation:

1. We start by checking if the length of the list is less than or equal to 1. In such cases, the list is considered sorted, so we return `True`.
2. We initialize `prev_num` to the first element of the list and `prev_count` to 1. These variables will keep track of the previous number encountered and its count.
3. We iterate through the list starting from the second element (index 1).
4. Inside the loop, we compare the current element `lst[i]` with the previous number `prev_num`.
* If they are equal, we increment `prev_count` by 1. If `prev_count` becomes greater than 2, it means we have more than one duplicate of the same number, so we return `False`.
* If the current element is less than the previous number, it means the list is not sorted in ascending order, so we return `False`.
* Otherwise, we update `prev_num` to the current element and reset `prev_count` to 1.
5. If we reach the end of the loop without returning `False`, it means the list is sorted and we return `True`.

Now you can use the `is_sorted` function to check if a list of numbers is sorted in ascending order, considering the given conditions.
passed
zhipu To complete the function `is_sorted` as per the given specifications, we need to ensure two conditions are met:

1. The list should be in ascending order.
2. No number should appear more than once.

Here is the complete Python code that fulfills these requirements:

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.

Examples
is_sorted([5]) ➞ True
is_sorted([1, 2, 3, 4, 5]) ➞ True
is_sorted([1, 3, 2, 4, 5]) ➞ False
is_sorted([1, 2, 3, 4, 5, 6]) ➞ True
is_sorted([1, 2, 3, 4, 5, 6, 7]) ➞ True
is_sorted([1, 3, 2, 4, 5, 6, 7]) ➞ False
is_sorted([1, 2, 2, 3, 3, 4]) ➞ True
is_sorted([1, 2, 2, 2, 3, 4]) ➞ False
'''
# Check if the list is sorted in ascending order
if lst != sorted(lst):
return False

# Check if there are more than one duplicate of the same number
for num in lst:
if lst.count(num) > 1:
return False

return True

# Test cases
print(is_sorted([5])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5])) # ➞ False
print(is_sorted([1, 2, 3, 4, 5, 6])) # ➞ True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # ➞ True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # ➞ False
print(is_sorted([1, 2, 2, 3, 3, 4])) # ➞ True
print(is_sorted([1, 2, 2, 2, 3, 4])) # ➞ False
```

### Explanation:
1. **Check if the list is sorted in ascending order**:
- We compare the original list `lst` with a sorted version of itself using `sorted(lst)`. If they are not the same, the list is not sorted in ascending order, and we return `False`.

2. **Check for duplicates**:
- We iterate through each number in the list and use the `count` method to determine how many times each number appears. If any number appears more than once, we return `False`.

3. **Return `True` if both conditions are met**:
- If the list passes both checks, it means the list is sorted in ascending order and has no more than one duplicate of any number, so we return `True`.

This implementation ensures that the function behaves as specified in the examples provided.
failed: This prints if this assert fails 7 (good for debugging!)
gpto1 To meet the requirements specified in the problem description, we'll create a function `is_sorted(lst)` that will perform two main checks:

1. **Sorted Order Check**: Verify that the list is sorted in ascending order. This means each element should be less than or equal to the next element.
2. **Duplicate Count Check**: Ensure that no number appears more than twice in the list.

Since the list is assumed to be of non-negative integers and possibly contains duplicates, we need an efficient way to count duplicates without using extra space for storing counts, especially since the list may be large.

Here's the implementation:

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.
'''
# Check if the list is sorted in ascending order
for i in range(len(lst)-1):
if lst[i] > lst[i+1]:
return False

# Check that no number appears more than twice
count = 1 # Initialize count for the first element
for i in range(1, len(lst)):
if lst[i] == lst[i-1]:
count += 1
if count > 2:
return False # More than two duplicates found
else:
count = 1 # Reset count for a new number

return True
```

**Explanation:**

- **Sorted Order Check**: The first `for` loop iterates through the list and checks if each element is less than or equal to the next. If it finds any element that is greater than the next one, it returns `False`.

- **Duplicate Count Check**: The second `for` loop, starting from the second element, checks if the current element is the same as the previous one. If it is, it increments the `count`. If the `count` exceeds 2, it means the number appears more than twice, and the function returns `False`. If the current element is different, it resets the `count` to 1.

**Test Cases:**

Let's test the function with the provided examples:

```python
print(is_sorted([5])) # Output: True
print(is_sorted([1, 2, 3, 4, 5])) # Output: True
print(is_sorted([1, 3, 2, 4, 5])) # Output: False
print(is_sorted([1, 2, 3, 4, 5, 6])) # Output: True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # Output: True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # Output: False
print(is_sorted([1, 2, 2, 3, 3, 4])) # Output: True
print(is_sorted([1, 2, 2, 2, 3, 4])) # Output: False
```

All the test cases should produce outputs as expected according to the problem description.
passed
deepseekv3 To complete the `is_sorted` function, we need to check two conditions:

1. The list is sorted in ascending order.
2. The list does not contain more than one duplicate of the same number.

Here’s the implementation of the function:

```python
def is_sorted(lst):
'''
Given a list of numbers, return whether or not they are sorted
in ascending order. If list has more than 1 duplicate of the same
number, return False. Assume no negative numbers and only integers.

Examples
is_sorted([5]) ➞ True
is_sorted([1, 2, 3, 4, 5]) ➞ True
is_sorted([1, 3, 2, 4, 5]) ➞ False
is_sorted([1, 2, 3, 4, 5, 6]) ➞ True
is_sorted([1, 2, 3, 4, 5, 6, 7]) ➞ True
is_sorted([1, 3, 2, 4, 5, 6, 7]) ➞ False
is_sorted([1, 2, 2, 3, 3, 4]) ➞ True
is_sorted([1, 2, 2, 2, 3, 4]) ➞ False
'''
# Check if the list is sorted in ascending order
if lst != sorted(lst):
return False

# Check if any number has more than one duplicate
from collections import Counter
count = Counter(lst)
for num, cnt in count.items():
if cnt > 2:
return False

return True

# Test cases
print(is_sorted([5])) # True
print(is_sorted([1, 2, 3, 4, 5])) # True
print(is_sorted([1, 3, 2, 4, 5])) # False
print(is_sorted([1, 2, 3, 4, 5, 6])) # True
print(is_sorted([1, 2, 3, 4, 5, 6, 7])) # True
print(is_sorted([1, 3, 2, 4, 5, 6, 7])) # False
print(is_sorted([1, 2, 2, 3, 3, 4])) # True
print(is_sorted([1, 2, 2, 2, 3, 4])) # False
```

### Explanation:
1. **Sorting Check**: The function first checks if the list is equal to its sorted version. If not, it returns `False`.
2. **Duplicate Check**: The function then uses the `Counter` from the `collections` module to count the occurrences of each number in the list. If any number appears more than twice, it returns `False`.
3. If both checks pass, the function returns `True`.

This implementation ensures that the list is both sorted and does not contain more than one duplicate of any number.
passed