GERALD04 - Editorial

editorial
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PROBLEM LINK:

Practice
Contest

Author: Gerald Agapov
Tester: Tasnim Imran Sunny
Editorialist: Jingbo Shang

DIFFICULTY:

Cakewalk

PREREQUISITES:

Programming

PROBLEM:

GF — (t2 - t1) — Chef — dist — Home

Given t1, t2, dist, determine the time costs before GF see the gift of two plans:

  1. Chef waits for GF, and then goes
    home together.
  2. Chef returns home first, and goes back to GF.

EXPLANATION:

For the first plan, the answer should be (t2 - t1) + dist.

For the second one, it will be a little complicated. We need to discuss in 2 cases:

  1. If dist + dist <= t2 - t1, then Chef can return the bus station before GF arrived. Therefore, the answer should be t2 - t1.
  2. If t2 - t1 < dist + dist, then they will meet at the trip of going back. Therefore, the answer should be the middle point of the trip (imagine that the three parts as a whole): (t2 - t1 + dist * 2) / 2.

AUTHOR’S AND TESTER’S SOLUTIONS:

Author’s solution can be found here.
Tester’s solution can be found here.

3 Likes
2

Solutions are redirecting to this page itself!

3

they will be updated soon I guess. You can check solutions of people who got AC by going over to the contest problem link

4

solutions are uploaded…check out

5

for the second type of plan you have written that there are 3 cases but you have written only 2

6

There are just 2 cases.

There are 3 types of people: those who can count and those who can’t :smiley:

7

Why was my code getting WA? Wasn’t it basically the same thing?
http://www.codechef.com/viewsolution/3122236

8

Please Explain “the answer should be the middle point of the trip” in the second case?

9

Chef and his gf can meet at the middle point of the trip if and only if the difference in times between time1 and time2 = dist. Since this hasn’t been mentioned in the question explicitly, we can’t assume this thing. So can u plz explain once again ?

10

why is it necessary that chef and girlfriend meet at the middle point?

11

https://www.codechef.com/viewsolution/14258608

why is it giving me a WA?

12

I am not able to understand how will they meet at the middle only…anyone please explain