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Python program to check if the list contains three consecutive common numbers in Python
• Difficulty Level : Hard
• Last Updated : 17 Aug, 2020

Our task is to print the element which occurs 3 consecutive times in a Python list.

Example :

```Input : [4, 5, 5, 5, 3, 8]

Output : 5

Input : [1, 1, 1, 64, 23, 64, 22, 22, 22]

Output : 1, 22
```

Approach :

1. Create a list.
2. Create a loop for range size – 2.
3. Check if the element is equal to the next element.
4. Again check if the next element is equal to the next element.
5. If both conditions are satisfied then print the element.

Example 1 : Only one occurrence of a 3 consecutively occurring element.

 `# creating the array``arr ``=` `[``4``, ``5``, ``5``, ``5``, ``3``, ``8``]`` ` `# size of the list``size ``=` `len``(arr)`` ` `# looping till length - 2``for` `i ``in` `range``(size ``-` `2``):`` ` `    ``# checking the conditions``    ``if` `arr[i] ``=``=` `arr[i ``+` `1``] ``and` `arr[i ``+` `1``] ``=``=` `arr[i ``+` `2``]:`` ` `        ``# printing the element as the ``        ``# conditions are satisfied ``        ``print``(arr[i])`

Output :

`5`

Example 2 : Multiple occurrences of 3 consecutively occurring elements.

 `# creating the array``arr ``=` `[``1``, ``1``, ``1``, ``64``, ``23``, ``64``, ``22``, ``22``, ``22``]`` ` `# size of the list``size ``=` `len``(arr)`` ` `# looping till length - 2``for` `i ``in` `range``(size ``-` `2``):`` ` `    ``# checking the conditions``    ``if` `arr[i] ``=``=` `arr[i ``+` `1``] ``and` `arr[i ``+` `1``] ``=``=` `arr[i ``+` `2``]:`` ` `        ``# printing the element as the ``        ``# conditions are satisfied ``        ``print``(arr[i])`

Output :

```1
22
```

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