108  Maximum Sum
Moderator: Board moderators
phew!
if anyone gets stuck with 108, plz note that this type of problems are very usual.. i was surprised to see how many 'almost same' are there!
and you can read the ioi 05 task garden's solution  just to get a good and easy understanding! seriously! i am not joking! (though 108 is a subproblem of garden)
http://www.ioi2005.pl/olympiad/ is the address!
if anyone gets stuck with 108, plz note that this type of problems are very usual.. i was surprised to see how many 'almost same' are there!
and you can read the ioi 05 task garden's solution  just to get a good and easy understanding! seriously! i am not joking! (though 108 is a subproblem of garden)
http://www.ioi2005.pl/olympiad/ is the address!
fahim
#include <smile.h>
#include <smile.h>

 New poster
 Posts: 3
 Joined: Sat Sep 08, 2007 2:38 am
In this situation, you just count the number of nested loops.
If you want to learn more, read this:
http://www.topcoder.com/tc?module=Stati ... omplexity1
If you want to learn more, read this:
http://www.topcoder.com/tc?module=Stati ... omplexity1
Thiago Sonego Goulart  UFMG/Brazil
WA in Prob 108
Code: Select all
#include<iostream>
using namespace std;
int size;
int M[100][100];
long long partialSum[100][100];
int main()
{
cin >> size;
for (int i = 0; i < size; i ++)
for (int j = 0; j < size; j ++)
cin >> M[i][j];
if (size <= 0)
{
cout << 0 << endl;
return 0;
}
long long MaxSum = 4147483647;
partialSum[0][0] = M[0][0];
for (int i = 1; i < size; i++)
partialSum[0][i] = partialSum[0][i  1] + M[0][i];
for (int i = 1; i < size; i++)
{
partialSum[i][0] = partialSum[i  1][0] + M[i][0];
for (int j = 1; j < size; j ++)
{
partialSum[i][j] = partialSum[i][j  1]  partialSum[i  1][j  1] + partialSum[i  1][j] + M[i][j];
}
}
for (int i1 = 0; i1 < size; i1 ++)
for (int i2 = i1; i2 < size; i2 ++)
for (int j1 = 0; j1 < size; j1 ++)
for (int j2 = j1; j2 < size; j2 ++)
{
long long sum = 0;
if ((i1 == 0) && (j1 == 0)) sum = partialSum[i2][j2];
else if (i1 == 0) sum = partialSum[i2][j2]  partialSum[i2][j1  1];
else if (j1 == 0) sum = partialSum[i2][j2]  partialSum[i1  1][j2];
else sum = partialSum[i2][j2]  partialSum[i1  1][j2]  partialSum[i2][j1  1] + partialSum[i1  1][j1  1];
if (sum > MaxSum) MaxSum = sum;
}
cout << MaxSum << endl;
return 0;
}
could any body help?
your algorithm is right
your computation algorithm is right.
i think the problem is input. this is a multi input problem.
your program deals with only first case.
you have to input and compute till eof.
by the way, long long is not needed to compute sum;
int is enough in this problem.
i think the problem is input. this is a multi input problem.
your program deals with only first case.
you have to input and compute till eof.
by the way, long long is not needed to compute sum;
int is enough in this problem.
108, am I on wrong way ?
Hi,
I'm trying to solve the problem in C++
Tab is the input array, Tab2[j] is the sum from 0 to i and 0 to j in Tab
I can't assure at all wether this line : is correct or not, maybe it has to be checked first
PS : Here is only the part of my code where the error seems to be, I already have checked the useless parts
I'm trying to solve the problem in C++
Tab is the input array, Tab2[j] is the sum from 0 to i and 0 to j in Tab
Code: Select all
done
Code: Select all
tmp=Tab2[m][n]Tab2[m][j1]Tab2[i1][n]+Tab2[i1][j1];
PS : Here is only the part of my code where the error seems to be, I already have checked the useless parts
Last edited by Phob028 on Thu Feb 07, 2008 11:17 am, edited 1 time in total.
 emotional blind
 A great helper
 Posts: 383
 Joined: Mon Oct 18, 2004 8:25 am
 Location: Bangladesh
 Contact:
Re: 108, am I on wrong way ?
May be this will be correct
And from next time don't forget to post in existing related thread. If there is no thread exists related to your topic then you can create a new one. So search before post.
Code: Select all
tmp=Tab2[i][j]Tab2[m1][j]Tab2[i][n1]+Tab2[m1][n1];
Are you sure those parts are useless? So why to check those rather then remove..Phob028 wrote:PS : Here is only the part of my code where the error seems to be, I already have checked the useless parts
Thanks for your answer, next time I will post in the related topic
I think these parts are useless for finding the mistake(s), but that's my program :
The output with your correction is 1881017956. It was 9 before. It has to be 15 (with the sample output)
I think these parts are useless for finding the mistake(s), but that's my program :
Code: Select all
done
Last edited by Phob028 on Thu Feb 07, 2008 11:16 am, edited 1 time in total.
 emotional blind
 A great helper
 Posts: 383
 Joined: Mon Oct 18, 2004 8:25 am
 Location: Bangladesh
 Contact:
What about this line:
Code: Select all
tmp=Tab2[i][j](m?Tab2[m1][j]:0)(n?Tab2[i][n1]:0)+((m&n)?Tab2[m1][n1]:0);
Yeah, it works for the sample input, thanks !
I've found an other small mistake in my conditions :
but always got WA and I don't find an input that don't work :s
I've found an other small mistake in my conditions :
Code: Select all
done
Last edited by Phob028 on Thu Feb 07, 2008 11:15 am, edited 1 time in total.
 emotional blind
 A great helper
 Posts: 383
 Joined: Mon Oct 18, 2004 8:25 am
 Location: Bangladesh
 Contact:
 emotional blind
 A great helper
 Posts: 383
 Joined: Mon Oct 18, 2004 8:25 am
 Location: Bangladesh
 Contact:
Re: 108, am I on wrong way ?
i get a Time limit exceeded in problem 108, but
the max depth of loop of my program is only 2....
and i use c++...
who can tell me why??
the max depth of loop of my program is only 2....
and i use c++...
who can tell me why??
Re: 108, am I on wrong way ?
what do you mean by saying your max depth loop is only 2 ?
Do you mean your program runs in O(n^2) ? It's amazing.
I think O(n^3) and O(n^4) will get AC, and I don't know how to figure an O(n^2) solution..
Maybe you can paste your code here to make it clear.
Do you mean your program runs in O(n^2) ? It's amazing.
I think O(n^3) and O(n^4) will get AC, and I don't know how to figure an O(n^2) solution..
Maybe you can paste your code here to make it clear.