HDU 2830 Matrix Swapping II (hdu1505 's enhanced version)

#include <cstdio> #include <cstring> #include <algorithm> #define N 1005using namespace Std;const int    Inf=1<<30;char mat[n][n];int a[n][n];int l[n],r[n];int main () {int m,n;    memset (a,0,sizeof (0));            while (scanf ("%d%d", &m,&n) ==2) {for (int i=1;i<=m;i++) {scanf ("%s", mat[i]+1);                for (int j=1;j<=n;j++) {if (mat[i][j]== ' 1 ') a[i][j]=1;            else a[i][j]=0; }} for (int i=1;i<=m;i++) {for (int j=1;j<=n;j++) {if (a[i            ][j]==1) A[i][j]+=a[i-1][j];        }} int ans=-inf;            for (int i=1;i<=m;i++) {sort (a[i]+1,a[i]+1+n);                for (int j=1;j<=n;j++) {l[j]=j;            while (L[j]>1&&a[i][l[j]-1]>=a[i][j]) l[j]=l[l[j]-1];            }for (int j=n;j>=1;j--) {r[j]=j;            while (R[j]<n&&a[i][r[j]+1]>=a[i][j]) r[j]=r[r[j]+1];            } for (int j=1;j<=n;j++) {Ans=max (ans,a[i][j]* (r[j]-l[j]+1));    }} printf ("%d\n", ans); } return 0;}

HDU 2830 Matrix Swapping II (hdu1505 's enhanced version)