## 10385 - Duathlon

Moderator: Board moderators

### 10385 - Duathlon

How to solve 10385
Jucovschi Constantin
New poster

Posts: 9
Joined: Sat Oct 26, 2002 6:30 pm

Learning poster

Posts: 57
Joined: Sun Sep 29, 2002 12:00 pm
Location: in front of the monitor :-)

### 10385: POOR description

I was doing 10385, then i found something that i need to know
The speed of the contestants is km/h, m/s ??
Without this my algo cannot know the answer.

thanks in advance if someone can tell me
Miguel & Marina
Miguel Angel
Learning poster

Posts: 60
Joined: Tue Aug 13, 2002 2:39 am
Location: Mexico

### I can answer my question..

Km. / H
BTW, i did a mistake in my implementation which got me shock and got me confused about if it was Km/H.
Miguel & Marina
Miguel Angel
Learning poster

Posts: 60
Joined: Tue Aug 13, 2002 2:39 am
Location: Mexico

Any hints on how to avoid problems with rounding ? I can barely obtain the given answers and then only if I make some assumptions about rounding. If I try to be more accurate then the sample answer appears to be incorrect as it appears to be closer to 14.2839 or 14.28 and yet the answer given is 14.29.......
Caesum
Experienced poster

Posts: 225
Joined: Fri May 03, 2002 12:14 am
Location: UK

nevermind....... was just my miscomputations........
Caesum
Experienced poster

Posts: 225
Joined: Fri May 03, 2002 12:14 am
Location: UK

### Re: 10385 - Duathlon

What's the output for this?

Code: Select all
`10012 3723 44 3100925 2040 1237 239 4917 1933 567 334 1121 30`
serur
A great helper

Posts: 251
Joined: Thu Feb 23, 2006 11:30 pm

### Re: 10385 - Duathlon

Hi serur.

I checked with assert that n is greater than 1.

Input:
Code: Select all
`723 44 3100925 2040 1237 239 4917 1933 567 334 1121 30`

My output:
Code: Select all
`The cheater can win by 2099 seconds with r = 7.00km and k = 0.00km.The cheater can win by 1270 seconds with r = 21.53km and k = 78.47km.`

Hope it helps.
coze
New poster

Posts: 26
Joined: Tue Nov 27, 2007 7:56 am
Location: Japan

### Re: 10385 - Duathlon

Thanks coze. This is my source code, it gets WA. What I did is a ternary search...

Code: Select all
`CUT AFTER AC`
Last edited by serur on Sat Sep 12, 2009 8:34 pm, edited 1 time in total.
If there is ever a war between men and machines, it is easy to guess who will start it (c) Arthur Clarke
serur
A great helper

Posts: 251
Joined: Thu Feb 23, 2006 11:30 pm

### Re: 10385 - Duathlon

Try using "%.0lf" instead of "%d".

Code: Select all
`printf("The cheater can win by %.0lf seconds with r = %.2lfkm and k = %.2lfkm.\n",       (f(left)),left,total-left);`
coze
New poster

Posts: 26
Joined: Tue Nov 27, 2007 7:56 am
Location: Japan

### Re: 10385 - Duathlon

Thanks coze, your suggestion was the very thing. Got it AC at last
If there is ever a war between men and machines, it is easy to guess who will start it (c) Arthur Clarke
serur
A great helper

Posts: 251
Joined: Thu Feb 23, 2006 11:30 pm

### Re: 10385 - Duathlon

what is the output for
Code: Select all
`1025 510 10`
New poster

Posts: 3
Joined: Thu Sep 24, 2009 2:05 am

### Re: 10385 - Duathlon

got accepted, it seems that no case on the judge similar to that one
New poster

Posts: 3
Joined: Thu Sep 24, 2009 2:05 am

### Re: 10385 - Duathlon

Remember to set precision to 0.001 if using ternary search! Caused me lots of headaches.
SePulTribe
New poster

Posts: 28
Joined: Mon Nov 15, 2004 5:00 pm

### Re: 10385 - Duathlon

Can someone the idea behind this ternary search solution?

Indeed, I really couldn't figure out how to solve this. I think something related to linear programming would do the job, but i looks like there are much simpler solutions than any using this kind of thing...

Best regards,
Douglas
docardoso
New poster

Posts: 1
Joined: Fri Jun 25, 2010 7:43 am

Next