Periodic Strings（周期字符串）

题目

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

1
HoHoHo

Sample Output

2

分析

这个题要求每组重复元素的个数，直接二重循环搜索即可，不过可以加一些条件加快搜索速度。

代码+注释

#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
int main()
{
    int n;
    string l;
    cin>>n;
    while(n--)
    {
        cin>>l;
        int a=l.size();         //求出输入字符串的大小。
        int flag=0;
        for(int i=1;i<=a;i++)          //第一重循环
        {

            if(a%i==0)               //剪枝
            {
                for(flag=i;flag<a;flag++)           //判断是否满足条件。
                {
                    if(l[flag%i]!=l[flag])           //若不满足，flag=0，停止第二重循环。
                    {
                        flag=0;
                        break;
                    }
                }
                    if(flag==0)            //若不满足，搜索下一组。
                    {
                        continue;
                    }
                    else if(flag==a)             //若满足，输出最小重复元素个数，停止第一重循环。
                    {
                        cout<<i<<endl;
                        break;
                    }
            }
        }
        if(n!=0)cout<<endl;
    }
    return 0;
}

标签：string,int,period,will,Periodic,blank,字符串,input,Strings
来源： https://blog.csdn.net/weixin_43105110/article/details/88082067