Circular Sequence

最新推荐文章于 2021-12-24 09:56:02 发布

月落乌啼霜月落

最新推荐文章于 2021-12-24 09:56:02 发布

阅读量523

点赞数 1

CC 4.0 BY-SA版权

分类专栏：字符串文章标签：字符串 UVa SDUT 字典序

本文链接：https://blog.youkuaiyun.com/zb756999355/article/details/55676669

字符串专栏收录该内容

18 篇文章

订阅专栏

本文介绍了一个关于环形DNA序列的问题，目标是找到并输出从给定的环形序列中所能得到的字典序最小的线性序列。通过不断循环移位并比较不同位置切割得到的线性序列，最终确定最小字典序。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Think:
直接比较每次后移一位与之前的字典序的大小　也就是　strcmp(s1,s2)

题目

Some DNA sequences exist in circular forms as in the following figure, which shows a circular sequence CGAGTCAGCT", that is, the last symbolT” in CGAGTCAGCT" is connected to the first symbolC”. We always read a circular sequence in the clockwise direction.

Since it is not easy to store a circular sequence in a computer as it is, we decided to store it as a linear sequence. However, there can be many linear sequences that are obtained from a circular sequence by cutting any place of the circular sequence. Hence, we also decided to store the linear sequence that is lexicographically smallest among all linear sequences that can be obtained from a circular sequence.

Your task is to find the lexicographically smallest sequence from a given circular sequence. For the example in the figure, the lexicographically smallest sequence is “AGCTCGAGTC”. If there are two or more linear sequences that are lexicographically smallest, you are to find any one of them (in fact, they are the same).

Input

The input consists of T test cases. The number of test cases T is given on the first line of the input file. Each test case takes one line containing a circular sequence that is written as an arbitrary linear sequence. Since the circular sequences are DNA sequences, only four symbols, A,C, G and T, are allowed. Each sequence has length at least 2 and at most 100.

Output

Print exactly one line for each test case. The line is to contain the lexicographically smallest sequence for the test case.

The following shows sample input and output for two test cases.

Sample Input

2
CGAGTCAGCT
CTCC

Sample Output

AGCTCGAGTC
CCCT

题目大意：
１．一个环形字符串
２．顺时针移动
２．要求输出最小的字典序

#include<stdio.h>
#include<string.h>



int main()
 {
 char str[1050];
char vis[1050];
  int T;
  scanf("%d",&T);
  while(T --)
   {
     scanf("%s",str);
     int d = strlen(str);
     int i;
     char c;
     strcpy(vis, str);
     int j;
     for (i = 0;i <= d - 1;i ++)
      {
         c = str[d - 1];
         for (j = d - 1;j >= 1;j --)
            {
              str[j] = str[j - 1];
            }
          str[0] = c;
          if (strcmp(vis,str) > 0)
              {
                strcpy(vis,str);
              }
      }
      puts(vis);
   }
  return 0;
 }