Advanced · Sorting algorithms · 173 of 264
By length, then alphabet
Sort words by length, shortest first; words of the same length alphabetically (capital letters don't matter for the order).
Input: words on one line. Output: the sorted words.
Examples
Input
banana kiwi apple fig
Output
fig kiwi apple banana
Input
a B c
Output
a B c
Input
Delta alpha Charlie bravo
Output
alpha bravo Delta Charlie
One more test checks other inputs when you press Check.
Stuck? The idea behind sorting algorithms
Bubble sort swaps neighbours that are in the wrong order, pass after pass. Insertion sort takes each item in turn and slides it back into place among those before it. Merge sort splits the list, sorts each half and merges them.
These exercises ask for the steps, not just the result: write the algorithm yourself rather than calling sorted().
a = [5, 1, 4, 2]
for end in range(len(a) - 1, 0, -1):
for i in range(end):
if a[i] > a[i + 1]:
a[i], a[i + 1] = a[i + 1], a[i]
print(a)Watch for: Off-by-one: comparing a[i] with a[i + 1] means i must stop one before the end.