Intermediate · Sorting · 149 of 264

Nearest points

Sort points by their distance from (0, 0), nearest first. Points at the same distance go in the order they were given.

Input: n, then n lines "x y". Output: the points, one per line, as x y

Examples

Input

Output

1 1
0 2
3 4

Input

1
5 5

Output

5 5

One more test checks other inputs when you press Check.

Stuck? The idea behind sorting

sorted() gives a new sorted list; list.sort() sorts the list itself. reverse=True sorts from largest to smallest.

key= says what to sort by: key=len sorts words by length, key=lambda p: p[1] sorts pairs by their second item.

people = [("Ann", 14), ("Bob", 12)]
for name, age in sorted(people, key=lambda p: p[1]):
    print(name, age)

Watch for: list.sort() gives back None: names = names.sort() loses the list. Use sorted() for a new one.