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# Python | Find Maximum difference pair

• Last Updated : 29 Apr, 2019

Sometimes, we need to find the specific problem of getting the pair which yields the maximum difference, this can be solved by sorting and getting the first and last elements of the list. But in some case, we don’t with to change the ordering of list and perform some operation in a similar list without using extra space. Let’s discuss certain ways in which this can be performed.

Method #1 : Using list comprehension + `max()` + `combination()` + lambda

This particular task can be performed using the combination of above functions in which we use list comprehension to bind all the functionalities and max function to get the maximum difference, combination function finds all differences internally and lambda function is used to compute the difference.

 `# Python3 code to demonstrate``# maximum difference pair``# using list comprehension + max() + combinations() + lambda``from` `itertools ``import` `combinations`` ` `# initializing list``test_list ``=` `[``3``, ``4``, ``1``, ``7``, ``9``, ``1``]`` ` `# printing original list``print``(``"The original list : "` `+` `str``(test_list))`` ` `# using list comprehension + max() + combinations() + lambda``# maximum difference pair``res ``=` `max``(combinations(test_list, ``2``), key ``=` `lambda` `sub: ``abs``(sub[``0``]``-``sub[``1``]))`` ` `# print result``print``(``"The maximum difference pair is : "` `+` `str``(res))`
Output :
```The original list : [3, 4, 1, 7, 9, 1]
The maximum difference pair is : (1, 9)
```

Method #2 : Using list comprehension + `nlargest()` + `combination()` + lambda

This method has potential of not only finding a single maximum but also k maximum difference pairs if required and uses nlargest function instead of max function to achieve this functionality.

 `# Python3 code to demonstrate``# maximum difference pair``# using list comprehension + nlargest() + combinations() + lambda``from` `itertools ``import` `combinations``from` `heapq ``import` `nlargest`` ` `# initializing list``test_list ``=` `[``3``, ``4``, ``1``, ``7``, ``9``, ``8``]`` ` `# printing original list``print``(``"The original list : "` `+` `str``(test_list))`` ` `# using list comprehension + max() + combinations() + lambda``# maximum difference pair``# computes 2 maximum pair differences``res ``=` `nlargest(``2``, combinations(test_list, ``2``), ``         ``key ``=` `lambda` `sub: ``abs``(sub[``0``]``-``sub[``1``]))`` ` `# print result``print``(``"The maximum difference pair is : "` `+` `str``(res))`
Output :
```The original list : [3, 4, 1, 7, 9, 8]
The maximum difference pair is : [(1, 9), (1, 8)]
```

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