HDU 1505 City game

Http://acm.hdu.edu.cn/showproblem.php? PID = 1, 1505

First, process the bottom-up height of each row and then process the left and right sides.

 1 #include <cstdio> 2 #include <cstring> 3 #include <algorithm> 4 #define maxn 1001 5 using namespace std; 6  7 int t; 8 int n,m; 9 int a[maxn][maxn];10 int l[maxn],r[maxn];11 12 int main()13 {14     scanf("%d",&t);15     while(t--)16     {17         scanf("%d%d",&n,&m);18         getchar();19         memset(a,0,sizeof(a));20         for(int i=1; i<=n; i++)21         {22             for(int j=1; j<=m; j++)23             {24                 char s[10];25                 scanf("%s",s);26                 if(s[0]==‘F‘) a[i][j]=a[i-1][j]+1;27                 else a[i][j]=0;28             }29         }30         int max1=-1;31         for(int i=1; i<=n; i++)32         {33             a[i][0]=a[i][m+1]=-1;34             for(int j=1; j<=m; j++)35                 l[j]=r[j]=j;36             for(int j=1; j<=m; j++)37             {38                 while(a[i][j]<=a[i][l[j]-1]) l[j]=l[l[j]-1];39             }40             for(int j=m; j>=1; j--)41             {42                 while(a[i][j]<=a[i][r[j]+1]) r[j]=r[r[j]+1];43             }44             for(int j=1; j<=m; j++)45             {46                 int ans=a[i][j]*(r[j]-l[j]+1);47                 if(ans>max1)48                     max1=ans;49             }50         }51         printf("%d\n",max1*3);52     }53     return 0;54 }

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