CAPTCHA zju 校赛 acm
CAPTCHA
Time Limit: 1 Second Memory Limit: 32768 KB
A CAPTCHA (Completely Automated Public Turing Test to Tell Computers and Humans Apart) is a program that generates and grades tests that are human solvable, but intends to be beyond the capabilities of current computer programs. This technology is now almost a standard security mechanism for defending against undesirable or malicious Internet bot programs, such as those spreading junk emails and those grabbing thousands of free email accounts instantly.
It is hard for you to make a program to solve it. So, in this moment, you just need to solve a much easier problem.
111111MMM1111111 1MMMMMMMMMMM1111 11111MMMMMMMM111 1MMMMMMMMMMM1111 1MMMMMMMMMMMM111 1MMMMMMMMMMMMM11 11111MM1MM111111 1MM11111111MM111 111MM1111111MM11 1MM111111111MM11 1MM1111111111111 1MM1111111111111 1111MM111MM11111 1MM11111111MM111 11MM111111111MM1 1MM1111111111MM1 1MM1111111111111 1MM1111111111111 111MMMMMMMMM1111 1MMMMMMMMMMM1111 11MM111111111111 1MM1111111111MM1 1MMMMMMMMMMMM111 1MMMMMMMMMMMMM11 11MM1111111MM111 1MM11111111MM111 11MM111111111MM1 1MM1111111111MM1 1MM1111111111111 1MM1111111111111 1MMM11111111MM11 1MM11111111MM111 111MM1111111MM11 1MM111111111MM11 1MM1111111111111 1MM1111111111111 1MM1111111111MM1 1MMMMMMMMMMM1111 11111MMMMMMMM111 1MMMMMMMMMMM1111 1MMMMMMMMMMMM111 1MM1111111111111 11111MMMMMMMM111 1MM111111111MM11 11111MMMMMM11111 1111MMMMMMMM1111 11MM111111MMM111 11MM111111111111 111MM1111111MM11 1MM111111111MM11 1111111MM1111111 1111111MM1111111 11MM11111MMM1111 11MM111111111111 11MM111111111MM1 1MM111111111MM11 1111111MM1111111 1111111MM1111111 11MM111MMM111111 11MM111111111111 11MM111111111111 1MMMMMMMMMMMMM11 1111111MM1111111 1111111MM1111111 11MMMMM111111111 11MM111111111111 11MM111111MMMMM1 1MM111111111MM11 1111111MM1111111 111MM11MM1111111 11MM111MMM111111 11MM111111111111 111MM1111111MM11 1MM111111111MM11 1111111MM1111111 111MMM1MM1111111 11MM11111MMM1111 11MM111111111111 11111MMMMMMMMM11 1MM111111111MM11 11111MMMMMM11111 11111MMMM1111111 11MM111111MMMM11 11MMMMMMMMMMMM11 1MM1111111111MM1 1MMM111111111MM1 11111MMMMMM11111 1MMMMMMMMMMM1111 11111MMMMMM11111 1MMMMMMMMMMM1111 1MMMM111111MMMM1 1MMMM11111111MM1 111MMM1111MMM111 1MM111111111MM11 111MMM1111MMM111 1MM111111111MM11 1MM1MM1111MM1MM1 1MM1MM1111111MM1 11MMM111111MMM11 1MM1111111111MM1 11MMM111111MMM11 1MM1111111111MM1 1MM11MMMMM111MM1 1MM11MM111111MM1 1MM1111111111MM1 1MM111111111MM11 1MM1111111111MM1 1MM111111111MM11 1MM1111M11111MM1 1MM1111MM1111MM1 11MMM111111MMM11 1MMMMMMMMMMM1111 11MMM1MMMM1MMM11 1MMMMMMMMMMM1111 1MM1111111111MM1 1MM111111MMM1MM1 111MMM1111MMM111 1MM1111111111111 111MMM11MMMMM111 1MM11111111MM111 1MM1111111111MM1 1MM11111111MMMM1 11111MMMMMM11111 1MM1111111111111 111111MMMM1MMMM1 1MM111111111MMM1 1111MMMMMMMM1111 11MMMMMMMMMMMM11 1MM1111111111MM1 1MMMM111111MMMM1 1MM1111111111MM1 11MMM111111MMM11 111MM1111111MM11 11MMMMMMMMMMMM11 1MM1111111111MM1 11MMM111111MMM11 1MM1111111111MM1 111MMM1111MMM111 11MMM1111111MMM1 1111111MM1111111 1MM1111111111MM1 11MMM111111MMM11 11MM111MM111MM11 1111MMM11MMM1111 1111MMMMM1111111 1111111MM1111111 1MM1111111111MM1 111MMM1111MMM111 11MM111MM111MM11 111111MMMM111111 1MMM111MMMM11111 1111111MM1111111 1MMM11111111MMM1 1111MMM11MMM1111 11MM111MM111MM11 1111MMM11MMM1111 111MMM11111MMM11 1111111MM1111111 1MMM11111111MMM1 11111MM11MM11111 11MM1MM11MM1MM11 111MMM1111MMM111 11111MMMMMMM1111 1111111MM1111111 111MMMMMMMMMM111 111111MMMM111111 111MMM1111MMM111 11MMM111111MMM11 11MMM111111MMM11 111MMMMMMMMMM111 111MMM1111MMM111 1111111111MM1111 1111MMM11MMM1111 111111111MM11111 111111MMMM111111 11111111MM111111 1111111MM1111111 111111MM11111111 1111111MM1111111 11111MM111111111 1111111MM1111111 111MMMMMMMMMMM11
Assume that the CAPTCHA only consists of upper letters. As you see above, we use a 7 * 16 matrix to represent a letter. The matrix only consists of characters 'M' and '1'. You can make sure that the 'M' elements in each letter matrix are connected. It means the all 'M' elements in each letter matrix belong to only ONE component. One element is connected to its 8 neighboring elements. That is, (x - 1, y), (x + 1, y), (x, y - 1), (x, y + 1), (x - 1, y - 1), (x + 1, y - 1), (x - 1, y + 1), (x + 1, y + 1) are (x, y)'s neighbors and they are connected.
And you will be given a bigger matrix, like this:
11111MMMMMM111 1111111MM11111 1MM1111MM11111 1MM1111MM11111 1MM1111MM11111 1MM1111MM11111 1MM11MMMMMM111 1MM11111111111 1MMMMMMMMMMMM1
Your task is to tell which letters appear in this matrix. The answer for this sample is 'I' and 'L'.
What's more, the letter appears in the bigger matrix may rotate 180 degrees, like this:
1MM1111111111MM11111111111111MM1 1MM1111111111MM11111111111111MM1 1MM1111111111MM11111111111111MM1 1MM1111111111MM111MMMMMMMMMMMMM1 1MMM11111111MMM11111111111111MM1 1MMM11111111MMM11111111111111MM1 111MMMMMMMMMM11111MMMMMMMMMMMMM1
'F' and 'U' is the answer for this sample.
OK, it's time for you to finish this work.
Input
There are multiple cases (no more than 10). In the first line, two integers n and m (7 <= n, m <= 300) will be given. Following n lines give the matrix. Each line contains m characters. Each character will be either 'M' or '1'. You may assume that 'M' characters between any pair of letters in the matrix won't be connected, and each 'M' in the matrix belongs to one valid letter.
There is a blank line between cases.
Output
Output the characters appear in the matrix. If a letter appears more than once, just output it ONE time. Sort the answer in alphabet order.
Sample Input
7 32 1MM1111111111MM11111111111111MM1 1MM1111111111MM11111111111111MM1 1MM1111111111MM11111111111111MM1 1MM1111111111MM111MMMMMMMMMMMMM1 1MMM11111111MMM11111111111111MM1 1MMM11111111MMM11111111111111MM1 111MMMMMMMMMM11111MMMMMMMMMMMMM1 15 19 11111MMMMMMMM111111 111MM1111111MM11111 11MM111111111MM1111 11MM111111111111111 11MM111111MMMMM1111 111MM1111111MM11111 11111MMMMMMMMM11111 1111111111111111111 1111MMM111111111MM1 1111MMMM11111111MM1 1111MM1MM1111111MM1 1111MM11MM111111MM1 1111MM1111MM1111MM1 1111MM111111MMM1MM1 1111MM11111111MMMM1
Sample Output
FU GN
#include <iostream>
#include<algorithm>
using namespace std;
char map[305][305];
bool flag[305][305];
char arr[300];
int n,m,num,si,sj;
int dir[8][2]={0,1,0,-1,1,0,-1,0,-1,1,-1,-1,1,1,1,-1};
int ncount;
void dry(int i,int j)
{
int k;
flag[i][j]=true;
ncount++;
for(k=0;k<8;k++)
{
if(map[i+dir[k][0]][j+dir[k][1]]=='M'&&flag[i+dir[k][0]][j+dir[k][1]]==false)
dry(i+dir[k][0],j+dir[k][1]);
}
}
void clear(int i,int j)
{
int k;
map[i][j]='1';
ncount++;
for(k=0;k<8;k++)
{
if(map[i+dir[k][0]][j+dir[k][1]]=='M')
clear(i+dir[k][0],j+dir[k][1]);
}
}
int search()
{
int j;
for(j=0;j<16;j++)
{
if(map[si][sj+j]=='M') ;
else break;
}
return j;
}
char select34()
{
if(search()==2||search()==12)
return 'T';
else return 'C';
}
char select42()
{
if(search()==11)
return 'D';
else if (search()==2)
return 'M';
else return 'N';
}
char select36()
{
if(search()==13)
return 'F';
if(search()==4)
return 'K';
else
{
if(map[si+3][sj+2]=='M')
return 'K';
else return 'F';
}
}
char select38()
{
if(search()==8||search()==9)
return 'G';
else if (search()==11)
return 'P';
else if(search()==10)
return 'U';
else if(search()==2)
{
if(map[si+4][sj+2]=='M')
return 'U';
else return 'P';
}
}
char select40()
{
if(search()==2)
return 'W';
else if (search()==6)
return 'O';
else if(search()==4)
return 'V';
else if(search()==3)
{
if(map[si+1][sj-1]=='M')
return 'W';
return 'X';
}
}
char select43()
{
if(search()==11||search()==3)
return 'R';
else return 'S';
}
void trans(int number)
{
switch(number)
{
case 33:
arr[num++]='A';
break;
case 49:
arr[num++]='B';
break;
case 44:
arr[num++]='E';
break;
case 37:
arr[num++]='H';
break;
case 22:
arr[num++]='I';
break;
case 27:
arr[num++]='J';
break;
case 48:
arr[num++]='Q';
break;
case 31:
arr[num++]='Z';
break;
case 28:
arr[num++]='Y';
break;
case 24:
arr[num++]='L';
break;
case 34:
arr[num++]=select34();
break;
case 42:
arr[num++]=select42();
break;
case 36:
arr[num++]=select36();
break;
case 38:
arr[num++]=select38();
break;
case 40:
arr[num++]=select40();
break;
case 43:
arr[num++]=select43();
break;
}
}
int main()
{
int i,j;
while(scanf("%d%d",&n,&m)!=EOF)
{
num=0;
for(i=0;i<=300;i++)
{
for(j=0;j<=300;j++)
{
flag[i][j]=false;
map[i][j]='1';
}
}
for(i=1;i<=n;i++)
{
getchar();
for(j=1;j<=m;j++)
scanf("%c",&map[i][j]);
}
for(i=1;i<=n;i++)
{
for(j=1;j<=m;j++)
{
if(map[i][j]=='M')
{
ncount=0;
dry(i,j);
si=i;
sj=j;
trans(ncount);
clear(i,j);
}
}
}
sort(arr,arr+num);
for(i=0;i<num;i++)
{
printf("%c",arr[i]);
while(i+1<num && arr[i+1] == arr[i])
i ++;
}
printf("/n");
}
return 0;
}