## 847 - A Multiplication Game

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helloneo
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Posts: 516
Joined: Mon Jul 04, 2005 6:30 am
Location: Seoul, Korea
Try this input..

Code: Select all

``````100
200
300
400
500
600
700
800
900
1000
``````

My output

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``````Stan wins.
Ollie wins.
Ollie wins.
Stan wins.
Stan wins.
Stan wins.
Stan wins.
Stan wins.
Stan wins.
Stan wins.
``````
By the way, you can also change the title to what sohel suggested .. Vexorian
Learning poster
Posts: 100
Joined: Sat Aug 26, 2006 5:50 am
Maarten wrote:
why 13123 makes Stan the winner?
My AC program makes Ollie the winner for 13123. In fact, I'd like to know very much your strategy to make Stan win. Wanna play a game of multiplication with n=13123? I will play Ollie, anyone volunteer to play Stan? My AC program makes Stan the winner for 13123.

Perhaps judge's I/O is not strong?
Life is NP-complete

vinicius_jssouza
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Posts: 1
Joined: Sat Dec 06, 2008 4:32 am

### Re: 847 - A Multiplication Game

Please, anybody tell me what's wrong with my approach?

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``````#include<iostream>

#define stan  true
#define ollie false

using namespace std;

int main()
{
long long n;
while (!feof(stdin) && cin >> n)
{
long long p = 1;

if (n <= 9)
{
cout << "Stan wins.\n";
continue;
}
{
long long mult = 9;
while (p * mult * 9 >= n && mult > 1)
mult--;
if (mult < 2) break;
p *= mult;
}
cout << "Ollie wins.\n";
else
cout << "Stan wins.\n";
}
return 0;
}
``````

pieguy
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Posts: 2
Joined: Tue Jun 23, 2009 8:39 pm

### Re: 847 - A Multiplication Game

This problem definitely has weak judge input. I accidentally read "2 OR 9" instead of "2 TO 9" and still got AC. My program should give the wrong output in roughly 25% of cases! (For example, my program claims that Ollie wins from 37 to 72, and that Stan wins from 325 to 648, etc.)

marco2509
New poster
Posts: 3
Joined: Wed Oct 28, 2009 10:59 pm

### Re: 847 - A Multiplication Game

Why I received runtime error.Remember to always terminate your code with the exit code 0.

Code: Select all

``````#include <stdio.h>
#include <string.h>
#include <math.h>
#include <iostream.h>

unsigned int n;

char w;

char getwin( int two,int three,int five,int seven ){
if ( w[two][three][five][seven] != -1 )
return w[two][three][five][seven];

long double x=1.0;

x*=pow( 2.0, two );
x*=pow( 3.0, three );
x*=pow( 5.0, five );
x*=pow( 7.0, seven );

if ( x+0.00000001 >= (long double)n ) return 0;

int k=0;
k+=!getwin(two+1,three,five,seven);
k+=!getwin(two,three+1,five,seven);
k+=!getwin(two+2,three,five,seven);
k+=!getwin(two,three,five+1,seven);
k+=!getwin(two+1,three+1,five,seven);
k+=!getwin(two,three,five,seven+1);
k+=!getwin(two+3,three,five,seven);
k+=!getwin(two,three+2,five,seven);

return w[two][three][five][seven]= k>0;
}

int main() {
FILE *in=fopen( "mult.txt", "r" );
int i,j,k;

while ( 1==fscanf( in, "%u", &n ) ){
memset( w, -1, sizeof(w) );
if ( getwin(0,0,0,0) )
printf( "Stan wins\n" );
else
printf( "Ollie wins\n" );
}
cin.get();
return 0;
}

``````

ericfode
New poster
Posts: 1
Joined: Tue Nov 10, 2009 3:23 am

### Re: 847 - A Multiplication Game

This is for problem 847
i am getting a incorrect answer from the judge
any ideas?
-eric

Code: Select all

``````
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <iostream>
unsigned long long n;

using namespace std;
int main( void ){

while (cin>>n)
{
cout <<endl;
if (n>55009980288) cout << "Ollie Wins." <<endl; else
if (n>612220032)cout<< "Stan Wins."<<endl ;else
if (n>306110016)cout<< "Ollie Wins."<<endl ;else
if (n>34012224)cout<< "Stan Wins."<<endl ;else
if (n>17006112)cout<< "Ollie Wins."<<endl ;else
if (n>1889568)cout<< "Stan Wins."<<endl ;else
if (n>944784)cout<< "Ollie Wins."<<endl ;else
if (n>104976)cout<< "Stan Wins."<<endl ;else
if (n>52488)cout<< "Ollie Wins."<<endl ;else
if (n>5832)cout<< "Stan Wins."<<endl ;else
if (n>2916)cout<< "Ollie Wins."<<endl ;else
if (n>324)cout<< "Stan Wins."<<endl ;else
if (n>162)cout<< "Ollie Wins."<<endl ;else
if (n>18)cout<< "Stan Wins."<<endl ;else
if (n>9)cout<< "Ollie Wins."<<endl ;else
if (n>=1)cout<< "Stan Wins."<<endl ;
}
}``````

seraph
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Posts: 9
Joined: Tue Dec 15, 2009 4:18 pm

### Re: 847 - A Multiplication Game

@ eric :
i know where is your mistake.

1. you should delete this line :

Code: Select all

``if (n>55009980288) cout << "Ollie Wins." <<endl; else``
2. The word 'Wins' in 'Stan Wins' and 'Ollie Wins' its should change to 'Stan wins' and 'Ollie wins'..     New poster
Posts: 28
Joined: Fri Mar 30, 2012 12:57 am

### Re: 847 - A Multiplication Game

Hi!
Could anybody tell me the reason why the following works:
If n <= 9, Stan wins
Else If n <= 9*2 Ollie wins
Else If n <= 9*2*9 Stan wins
Else If n <= 9*2*9*2, Ollie wins
...etc...
Thanks in advance! hello
New poster
Posts: 25
Joined: Sun Mar 10, 2013 7:29 pm

### Re: 847 - A Multiplication Game

I really don't understand the problem. What is the real gameplan of stan to select the number at first.The statement says
assume that both of them play perfectly
I think this might be the key. But I also don't understand the meaning of it.

brianfry713
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Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

### Re: 847 - A Multiplication Game

hello, there is a strategy for the winner to follow that no matter what numbers his opponent chooses he will always win.
Check input and AC output for thousands of problems on uDebug!

hello
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Posts: 25
Joined: Sun Mar 10, 2013 7:29 pm

### Re: 847 - A Multiplication Game

Then why Ollie always call 2 in the second ? @brianfry713

brianfry713
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Posts: 5947
Joined: Thu Sep 01, 2011 9:09 am
Location: San Jose, CA, USA

### Re: 847 - A Multiplication Game

Ollie doesn't always multiply by 2 in the second round. For example if n = 15 then no matter what number Stan multiplies by if Ollie multiplies by 8 he will win.
Check input and AC output for thousands of problems on uDebug!