PROBLEM LINK:
Practice
Contest: Division 1
Contest: Division 2
Contest: Division 3
Contest: Division 4
Author: iceknight1093
Tester: iceknight1093
Editorialist: iceknight1093
DIFFICULTY:
Cakewalk
PREREQUISITES:
None
PROBLEM:
Find the minimum time needed to travel D kilometers, if you can teleport up to T kilometers at most once for no time cost, and otherwise walk one kilometer an hour.
EXPLANATION:
The teleport is free, so we might as well use it.
If D \le T then the teleport alone is enough to get us home, and the answer is 0.
If D \gt T, then the teleport shaves off at most T kilometers, and we have to walk the rest of the way.
It’s of course optimal to teleport exactly T kilometers, and that leaves D-T kilometers to walk.
At a rate of one kilometer per hour, that takes D-T hours to reach home.
TIME COMPLEXITY:
\mathcal{O}(1) per testcase.
CODE:
Editorialist's code (PyPy3)
d, t = map(int, input().split())
if t >= d: print(0)
else: print(d-t)