Given two strings a and b we define a*b to be their concatenation. For example, if a = "abc" and b = "def" then a*b = "abcdef". If we think of concatenation as multiplication, exponentiation by a non-negative integer is defined in the normal way: a^0 = "" (the empty string) and a^(n+1) = a*(a^n).
Input
Each test case is a line of input representing s, a string of printable characters. The length of s will be at least 1 and will not exceed 1 million characters. A line containing a period follows the last test case.
Output
For each s you should print the largest n such that s = a^n for some string a.
Sample Input
abcd aaaa ababab .
Sample Output
1 4 3
Hint
This problem has huge input, use scanf instead of cin to avoid time limit exceed.
题意 :找字符串中的最多的循环子串(必须连续)
题解:kmp的next数组求最小环,有一点必须注意,整个字符串必须都是循环构成的,否则就输出1
#include<map> #include<set> #include<cmath> #include<queue> #include<stack> #include<vector> #include<cstdio> #include<iomanip> #include<cstdlib> #include<cstring> #include<iostream> #include<algorithm> #define pi acos(-1) #define ll long long #define mod 1000000007 #define ls l,m,rt<<1 #define rs m+1,r,rt<<1|1 using namespace std; const double g=10.0,eps=1e-9; const int N=1000000+5,maxn=1000000+5,inf=0x3f3f3f3f; int Next[N],slen; string str; void getnext() { int k=-1; Next[0]=-1; for(int i=1;i<slen;i++) { while(k>-1&&str[k+1]!=str[i])k=Next[k]; if(str[k+1]==str[i])k++; Next[i]=k; } } int main() { ios::sync_with_stdio(false); cin.tie(0); // cout<<setiosflags(ios::fixed)<<setprecision(2); while(cin>>str){ if(str==".")break; slen=str.size(); getnext(); int ans=slen-Next[slen-1]-1; if(slen%ans)cout<<1<<endl; else cout<<slen/ans<<endl; } return 0; }