cf(思维题)

B. Rebranding
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

The name of one small but proud corporation consists of n lowercase English letters. The Corporation has decided to try rebranding — an active marketing strategy, that includes a set of measures to change either the brand (both for the company and the goods it produces) or its components: the name, the logo, the slogan. They decided to start with the name.

For this purpose the corporation has consecutively hired m designers. Once a company hires the i-th designer, he immediately contributes to the creation of a new corporation name as follows: he takes the newest version of the name and replaces all the letters xiby yi, and all the letters yi by xi. This results in the new version. It is possible that some of these letters do no occur in the string. It may also happen that xi coincides with yi. The version of the name received after the work of the last designer becomes the new name of the corporation.

Manager Arkady has recently got a job in this company, but is already soaked in the spirit of teamwork and is very worried about the success of the rebranding. Naturally, he can't wait to find out what is the new name the Corporation will receive.

Satisfy Arkady's curiosity and tell him the final version of the name.

Input

The first line of the input contains two integers n and m (1 ≤ n, m ≤ 200 000) — the length of the initial name and the number of designers hired, respectively.

The second line consists of n lowercase English letters and represents the original name of the corporation.

Next m lines contain the descriptions of the designers' actions: the i-th of them contains two space-separated lowercase English lettersxi and yi.

Output

Print the new name of the corporation.

Sample test(s)
input
6 1
police
p m
output
molice
input
11 6
abacabadaba
a b
b c
a d
e g
f a
b b
output
cdcbcdcfcdc
Note

In the second sample the name of the corporation consecutively changes as follows:


通过这一题让我们严重的认识到思维的重要性。。。。刚开始还以为要把整个串都做处理。。。T_T

事实上这题其实就是对26个字母做变换操作,就是要看26个字母最后怎么变!所以我们的眼光应该着眼于这26个字母上,所以对于整串的操作完全没有必要了。。。。

#include <iostream>
#include <cstdio>
#include <string.h>
#include<algorithm>
using namespace std;
char str[200010];
char a[26];

int main()
{
    int n,m;
    for(int i=0;i<26;i++)
    a[i]=i+'a';
    scanf("%d%d",&n,&m);
    scanf("%s",str);
    for(int i=0;i<m;i++)
    {
        char a1,a2;
        scanf(" %c %c",&a1,&a2);
        if(a1==a2)continue;
        for(int j=0;j<26;j++)
            if(a1==a[j])
            a[j]=a2;
            else if(a2==a[j])
            a[j]=a1;
    }
    for(int i=0;i<n;i++)
    printf("%c",a[str[i]-'a']);
    printf("\n");
    return 0;
}

posted @ 2015-10-30 14:22  martinue  阅读(269)  评论(0编辑  收藏  举报