【POJ 2406 Power Strings】
Time Limit: 3000MS
Memory Limit: 65536K
Description
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.
Source
Waterloo local 2002.07.01
题解:
①找出最小循环节————KMP
#include<stdio.h> #include<cstring> #define go(i,a,b) for(int i=a;i<=b;i++) const int N=4000003;int m,f[N],j;char P[N]; int main() { f[0]=f[1]=0; while(scanf("%s",P),m=strlen(P),P[0]!='.') { go(i,1,m-1){j=f[i];while(j&&P[i]!=P[j])j=f[j];f[i+1]=P[i]==P[j]?j+1:0;} printf("%d\n",m%(m-f[m])?1:m/(m-f[m])); } return 0; }//Paul_Guderian
镜子里面,像看到人生终点,或许再过上几年
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