首页 > ACM题库 > HDU-杭电 > hdu 2369 Broken Keyboard-字符串-[解题报告]C++
2014
01-05

hdu 2369 Broken Keyboard-字符串-[解题报告]C++

Broken Keyboard

问题描述 :

Bruce Force’s keyboard is broken, only a few keys are still working. Bruce has figured out he can still type texts by switching the keyboard layout whenever he needs to type a letter which is currently not mapped to any of the m working keys of the keyboard.

You are given a text that Bruce wishes to type, and he asks you if you can tell him the maximum number of consecutive characters in the text which can be typed without having to switch the keyboard layout. For simplicity, we assume that each key of the keyboard will be mapped to exactly one character, and it is not possible to type other characters by combination of different keys. This means that Bruce wants to know the length of the largest substring of the text which consists of at most m different characters.

输入:

The input contains several test cases, each test case consisting of two lines. The first line of each test case contains the number m (1 ≤ m ≤ 128), which specifies how many keys on the keyboard are still working. The second line of each test case contains the text which Bruce wants to type. You may assume that the length of this text does not exceed 1 million characters. Note that the input may contain space characters, which should be handled like any other character.

The last test case is followed by a line containing one zero.

输出:

The input contains several test cases, each test case consisting of two lines. The first line of each test case contains the number m (1 ≤ m ≤ 128), which specifies how many keys on the keyboard are still working. The second line of each test case contains the text which Bruce wants to type. You may assume that the length of this text does not exceed 1 million characters. Note that the input may contain space characters, which should be handled like any other character.

The last test case is followed by a line containing one zero.

样例输入:

5
This can't be solved by brute force.
1
Mississippi
0

样例输出:

7
2
Hint
The largest substring for the first test case is "_by_bru", where _ stands for a space character.

题目链接:http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=3139

题目大意:给定一个字符串,内部含有”【“和”】“光标转移指令,

【代表光标移向文章头,】代表光标移向文章尾,问最终在屏幕上显示的字符串序列是?

解题题报告人:GHQ(SpringWater)

解题思路:考虑到后面的【比总会前面的【使得,字符更加靠前,所以我就从右边考试需找【,找到就输出,

左边的】在序列里没起作用,所以不用管,遇到直接输出!看起来很简单,但是他这题最恶心的是,你不能将最终的

结果strcat到一个ans数组里,否则会超时,所以你只有直接输出!但这里还要注意的是,当你从左到右查找】之前,

必须判定开头是否已字母开头,单独处理一下就是了!

#include<string.h>
#include<stdio.h>
#define MAXN 100002
char s[MAXN],temp[MAXN];
int main()
{
    int i,len;
    while(~scanf("%s",s))
    {
        len=strlen(s);
        for(i = 0; i < len; ++i)
        {
            if(s[i]=='['||s[i]==']')
                temp[i] = '\0';
            else
                temp[i] = s[i];
        }
        temp[len]='\0';
        for(i = len - 1; i > -1; --i)
        {
            if(s[i]=='[')
                printf("%s",temp+i+1);
        }
        if(!(s[0]=='['||s[0]==']'))
            printf("%s",temp);
        for(i = 1; i < len; ++i){
            if(s[i]==']')
                printf("%s",temp+i+1);
        }
        printf("\n");
    }
    return 0;
}

解题转自:http://blog.csdn.net/sprintfwater/article/details/7925476


  1. 第2题,TCP不支持多播,多播和广播仅应用于UDP。所以B选项是不对的。第2题,TCP不支持多播,多播和广播仅应用于UDP。所以B选项是不对的。