Output list of numbers based on preference and threshold-CodePudding

I'm looking for some help in finding a suitable algorithm.

Here is my problem:

I have three sets of numbers. Each set represents a preference, and consists of n variables. I want to go over all of the variables in all sets, and output a list of the variables that fall within a given threshold from the highest number overall, from the highest possible set.

set 1: preferred set 2: second-most preferred set 3: last resort.

Threshold: 50

Example 1:

set 1: 100, 110, 120
set 2: 60, 70, 151
set 3 10, 20, 30

Should output: 110, 120 Taken from set 1. 100 should not be included, because the difference between the highest number overall (151) is more than the threshold of 50

Example 2:

set 1: 100, 110, 120
set 2: 100, 120, 161
set 3: 40, 50, 60

Should output: 120 Taken from set 1. 100, 110 should not be included because the difference between those and 161 is more than the threshold of 50.

Example 3:

set 1: 100, 110, 120
set 2: 151, 161, 100
set 3: 110, 120, 130

Should output: 120 Even though 151 and 161 are higher than all of the numbers in set 1, there still is a number that is within the threshold of 50, i.e. 120

Example 4:

set 1: 100, 110, 120
set 2: 151, 161, 200
set 3: 130, 140, 150

Should output: 151, 161, 200

Last example:

set 1: 100, 110, 120
set 2: 151, 161, 171,
set 3: 100, 200, 300

Should output: 200, 300

100 is not chosen because it's less than the threshold from the highest number (300), even though it's within the same set.

Would appreciate any help.

Thanks!

CodePudding user response：

This problem is not particularly subtle and doesn't require any particular data structure.

Find the maximum element;
Find the elements in the first set which are above maximum - threshold;
If you found at least one element at the previous step, return the found elements;
Otherwise, repeat with the second set; then the third set.

Example in python:

def find_preferred_numbers(s1, s2, s3, threshold=50):
    m = max(max(s1), max(s2), max(s3)) - threshold
    for s in (s1, s2, s3):
        results = [x for x in s if x >= m]
        if len(results) > 0:
            return results
    return []

examples = [
[[100, 110, 120],
[60, 70, 151],
[10, 20, 30]],

[[100, 110, 120],
[100, 120, 161],
[40, 50, 60]],

[[100, 110, 120],
[151, 161, 100],
[110, 120, 130]],

[[100, 110, 120],
[151, 161, 200],
[130, 140, 150]],

[[100, 110, 120],
[151, 161, 171],
[100, 200, 300]]
]

for i, (s1,s2,s3) in enumerate(examples, start=1):
    result = find_preferred_numbers(s1,s2,s3)
    print('example {}: {}'.format(i, result))

# example 1: [110, 120]
# example 2: [120]
# example 3: [120]
# example 4: [151, 161, 200]
# example 5: [300]