Codeforces 554B：Ohana Cleans Up（思维+水题）

B. Ohana Cleans Up

time limit per test
2 seconds

memory limit per test
256 megabytes

input
standard input

output
standard output

Ohana Matsumae is trying to clean a room, which is divided up into an n by n grid
of squares. Each square is initially either clean or dirty. Ohana can sweep her broom over columns of the grid. Her broom is very strange: if she sweeps over a clean square, it will become dirty, and if she sweeps over a dirty square, it will become clean.
She wants to sweep some columns of the room to maximize the number of rows that are completely clean. It is not allowed to sweep over the part of the column, Ohana can only sweep the whole column.

Return the maximum number of rows that she can make completely clean.

Input

The first line of input will be a single integer n (1 ≤ n ≤ 100).

The next n lines will describe the state of the room. The i-th
line will contain a binary string with n characters denoting the state of the i-th
row of the room. The j-th character on this line is '1' if the j-th
square in the i-th row is clean, and '0' if it is dirty.

Output

The output should be a single line containing an integer equal to a maximum possible number of rows that are completely clean.

Examples

input

4
0101
1000
1111
0101

output

2

input

3
111
111
111

output

3

Note

In the first sample, Ohana can sweep the 1st and 3rd columns. This will make the 1st and 4th row be completely clean.

In the second sample, everything is already clean, so Ohana doesn't need to do anything.

题目大意：一个女生要打扫房间，这个房间里面1代表干净的地方，0代表脏的地方，她每次挑选一些列，打扫这些列，她打扫的时候0会变成1,1会变成0，问她怎么选列打扫，打扫完之后能够使得干净的行数最多，输出干净的行数。

解题思路：看有多少个0、1完全一样的行，输出完全一样的最多的行数。

代码如下：

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int main()
{
int n;
scanf("%d",&n);
char map[110][110];
memset(map,0,sizeof(map));
for(int i=0;i<n;i++)
{
scanf("%s",map[i]);
}
int ans=0;
for(int i=0;i<n;i++)
{
int num=1;
for(int j=i+1;j<n;j++)
{
if(strcmp(map[i],map[j])==0)
{
num++;
}
}
ans=max(ans,num);
}
printf("%d\n",ans);
return 0;
}