Codeforces 90B-African Crossword

African Crossword

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

An African crossword is a rectangular table n × m in size. Each cell of the table contains exactly one letter. This table (it is also referred to as grid) contains some encrypted word that needs to be decoded.

To solve the crossword you should cross out all repeated letters in rows and columns. In other words, a letter should only be crossed out if and only if the corresponding column or row contains at least one more letter that is exactly the same. Besides, all such letters are crossed out simultaneously.

When all repeated letters have been crossed out, we should write the remaining letters in a string. The letters that occupy a higher position follow before the letters that occupy a lower position. If the letters are located in one row, then the letter to the left goes first. The resulting word is the answer to the problem.

You are suggested to solve an African crossword and print the word encrypted there.

Input

The first line contains two integers n and m (1 ≤ n, m ≤ 100). Next n lines contain m lowercase Latin letters each. That is the crossword grid.

Output

Print the encrypted word on a single line. It is guaranteed that the answer consists of at least one letter.

Examples

input

3 3
cba
bcd
cbc

output

abcd

input

5 5
fcofd
ooedo
afaoa
rdcdf
eofsf

output

codeforces

题意：给定一个字符矩阵，对于某个字符如果在同行或者同列有相同的字符出现，那么这个字符被标记，最后从上到下、从左到右输出所有未标记字符。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <queue>
#include <stack>using namespace std;char ch[105][105];
int visit[105][105];
int n,m;int check(int x,int y)
{int flag=0;for(int i=0;i<n;i++)if(i!=x&&ch[x][y]==ch[i][y]) visit[i][y]=1,flag=1;for(int i=0;i<m;i++)if(i!=y&&ch[x][y]==ch[x][i]) visit[x][i]=1,flag=1;return flag;
}int main()
{while(~scanf("%d %d",&n,&m)){memset(visit,0,sizeof visit);for(int i=0;i<n;i++)scanf("%s",ch[i]);for(int i=0;i<n;i++){for(int j=0;j<m;j++){int ans=check(i,j);if(ans) visit[i][j]=1;}}for(int i=0;i<n;i++){for(int j=0;j<m;j++)if(!visit[i][j]) printf("%c",ch[i][j]);}printf("\n");}return 0;
}

Codeforces 90B-African Crossword相关推荐

CodeForces 90B African Crossword【模拟】
African Crossword Time Limit:2000MS Memory Limit:262144KB 64bit IO Format:%I64d & %I64u ...
【codeforces 721A】One-dimensional Japanese Crossword
A. One-dimensional Japanese Crossword time limit per test 1 second memory limit per test 256 megabyt ...
【Codeforces】 Round #374 (Div. 2)
Position:http://codeforces.com/contest/721 我的情况开始还是rank1,秒出C.(11:00机房都走光了,我ma到11:05才走,只打了一个小时) 结果.. ...
Codeforces Round #374 (Div. 2) A. One-dimensional Japanese Crosswor 水题
A. One-dimensional Japanese Crossword 题目连接: http://codeforces.com/contest/721/problem/A Description ...
【Codeforces】A2组刷题记录（50 / 50）完结
目录 A1. Counterexample A2. Good Number A3. Dice Tower ★A4. Alyona and Numbers A5. Mountain Scenery rz ...
Educational Codeforces Round 105 (Rated for Div. 2) 题解
Educational Codeforces Round 105 (Rated for Div. 2) A. ABC String 枚举ABC分别为"( "和 " )&q ...
CodeForces 375D Tree and Queries
传送门:https://codeforces.com/problemset/problem/375/D 题意: 给你一颗有根树,树上每个节点都有其对应的颜色,有m次询问,每次问你以点v为父节点的子树内 ...
「日常训练」Bad Luck Island（Codeforces Round 301 Div.2 D）
题意与分析(CodeForces 540D) 是一道概率dp题. 不过我没把它当dp做... 我就是凭着概率的直觉写的,还好这题不算难. 这题的重点在于考虑概率:他们喜相逢的概率是多少?考虑超几何分布 ...
【codeforces 812C】Sagheer and Nubian Market
[题目链接]:http://codeforces.com/contest/812/problem/C [题意] 给你n个物品; 你可以选购k个物品;则每个物品有一个基础价值; 然后还有一个附加价值; ...

Codeforces 90B-African Crossword

Codeforces 90B-African Crossword相关推荐

最新文章

热门文章