UVa 455 - Periodic Strings

最新推荐文章于 2021-12-27 14:19:08 发布

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本文介绍了一个用于确定字符串最小周期的算法实现。通过输入一个由非空格字符组成的字符串，程序能够找出该字符串的最小重复周期。文章还提供了一个示例代码，包括输入输出示例，帮助理解算法的工作原理。

Periodic Strings

A character string is said to have period k if it can be formed by concatenating one or more repetitions of another string of length k. For example, the string “abcabcabcabc” has period 3, since it is formed by 4 repetitions of the string “abc”. It also has periods 6 (two repetitions of “abcabc”) and 12 (one repetition of “abcabcabcabc”).

Write a program to read a character string and determine its smallest period.

Input

The first line oif the input file will contain a single integer N indicating how many test case that your program will test followed by a blank line. Each test case will contain a single character string of up to 80 non-blank characters. Two consecutive input will separated by a blank line.

Output

An integer denoting the smallest period of the input string for each input. Two consecutive output are separated by a blank line.

Sample Input

HoHoHo

Sample Output

现在做题都是先看输入输出结果，此题一看就是水题啊，但是我卡住了。。。
为什么卡住，有待反思

AC

#include <stdio.h>
#include <string.h>
char str[81];

int main()
{
    int n;
    scanf("%d",&n);
    while(n--)
    {
        scanf("%s",str);
        getchar();
        int len=strlen(str);
        int t,i;
        for(t=1; t<=len; t++)//t为周期
        {
            if(len%t==0)
            {
                for(i=t; i<len; i++)//写成i=0，也是可以的，但是i=t更优
                    if(str[i%t]!=str[i])
                        break;//如果不满足循环条件就跳出循环
            }
            if(i==len)//如果上述循环顺利完成，i=n
            {
                printf("%d\n",t);
                if(n!=0)printf("\n");//此题的一个坑就是要控制输出格式，看书上是完全看不出来要输出控制的
                break;
            }
        }
    }
    return 0;
}