ENG  RUS Timus Online Judge
Online Judge
Problems
Authors
Online contests
Site news
Webboard
Problem set
Submit solution
Judge status
Guide
Register
Authors ranklist
Current contest
Scheduled contests
Past contests
Rules
back to board

## Discussion of Problem 1146. Maximum Sum

Posted by Gilgames Sumer 3 Nov 2007 03:05
I calculated every sum by columns and then used dp for finding largest in rows, I know there is an easy O(N^4) solution but I want this one

#include <stdio.h>

long i,j,k,n,max=-150,tmp=0,a[200][200];

main () {
scanf ("%d",&n);
for (i=0;i<n;i++)
for (j=0;j<n;j++) {
scanf ("%d",&a[i][j]);
if (a[i][j]>max) max=a[i][j];}
for (k=0;k<n;k++) {
if (k!=0)
for (i=n-1;i>=k;i--)
for (j=0;j<n;j++)
a[i][j]-=a[i-1][j];
for (i=k+1;i<n;i++)
for (j=0;j<n;j++)
a[i][j]+=a[i-1][j];
for (i=k;i<n;i++){
tmp=0;
for (j=0;j<n;j++){
tmp+=a[i][j];
if (max<tmp) max=tmp;
while (tmp<0) tmp=a[i][j++];
}
if (max<tmp) max=tmp;
}
}
printf ("%d",max);
}

Edited by author 03.11.2007 03:39

Edited by author 03.11.2007 03:39