UVA1584 - Circular Sequence 循环字符串比较的技巧
来源:互联网 发布:mac安装双系统win8 编辑:程序博客网 时间:2024/04/26 22:31
题目如下:
Some DNA sequences exist in circular forms as in the following figure, which shows a circular sequence ``CGAGTCAGCT", that is, the last symbol ``T" in ``CGAGTCAGCT" is connected to the first symbol ``C". 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 casesT 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
一开始拿到这个题,首先想到的是用多个数组储存每次变化后的字符串,然后用数组进行比较。这样做不仅会消耗大量空间和时间,程序也会特别繁琐。
让我们想一下问题的实质在哪里?
比较。
如何去比较?
肯定是对应元素一个一个比较。
换一种说法,就是两个差值恒定的下标作比较。我们只需要移动下标即可。
从这个角度看,我们发现这有点像在寻找 “最小值”:将两种元素以一定的方式进行比较。
代码如下:
#include<stdio.h>#include<string.h>int judge(char*A,int key, int p,int flag){while(key < flag) {//将元素一个一个进行比较 if(A[key%strlen(A)] > A[p%strlen(A)])return 1;else if(A[key%strlen(A)] == A[p%strlen(A)]) {key++;p++;if( judge(A,key,p,flag) )return 1;}else return 0;}}int main(){int T;char A[110];char B[110];scanf("%d",&T);while(T--){memset(A,0,sizeof(A));memset(B,0,sizeof(B));scanf("%s",A);int key=0,p=1;while(p<strlen(A)){//寻找使得“最小”成立的下标key int flag = key+strlen(A);if( judge(A,key,p,flag) )key = p;p++;}for(int i=0;i<strlen(A);i++){//找到下标key后,将数组转移到一个新的数组中,方便输出。 B[i] = A[key%strlen(A)];key++;}printf("%s\n",B);}
- UVA1584 - Circular Sequence 循环字符串比较的技巧
- UVa1584 - Circular Sequence
- UVA1584 - Circular Sequence
- uva1584 - Circular Sequence
- uva1584 Circular Sequence
- UVA1584 UVALive3225 Circular Sequence
- UVa1584 Circular Sequence
- UVa1584 - Circular Sequence
- UVa1584-Circular Sequence
- UVa1584——Circular Sequence
- UVa1584 环状序列 (Circular Sequence)
- Uva1584-环状序列-Circular Sequence-字典序
- 环状序列(Circular Sequence, ACM/ICPC Seoul 2004, UVa1584)
- uva1583 Digit Generator && uva1584 Circular Sequence(水)
- UVa1584 Circular Sequence(环状序列) (java版本)
- 环装序列 (Circular Sequence, ACM/ICPC Seoul 2004, UVa1584)
- 环状序列(Circular Sequence, ACM/ICPC Seoul 2004, UVa1584)
- Circular Sequence 字符串处理
- Windows下设置git对比和合入工具为beyond compare
- 获取目标文件夹下所有文件字节的大小及个数
- Linux 私房菜 笔记
- hibernate 分页后,查询总数 使用hql和sql
- 百度贴吧爬虫node+vue
- UVA1584 - Circular Sequence 循环字符串比较的技巧
- JAVA集合框架详解
- 键盘录入并统计该字符串中各个字符的数量
- Unity Editor 编辑器扩展 七 创建脚本模版
- IOS开发入门(2)
- iOS9 3DTouch 之 Home Screen Quick Actions
- Spring4 实战笔记(1):装配bean—依赖注入的本质
- Codeforces #383 div1 A
- Java学习笔记-IO流