UVA10298 Power Strings

求一个字符串由多少个重复的子串连接而成
先搞hash就好

const int N = 1e6 + 79;
char s[N];
int n;
char ch;
ull h[N], base = 131, hash[N];

inline ull H(int l, int r) {
	return hash[r] - hash[l - 1] * h[r-l+1];
}

inline bool check(int len,ull num){
	for(int l=1;l<=n;l+=len){
		if(H(l,l+len-1)!=num) return false;
	}
	return true;
}
/*
ababab
.
*/
int main() {
	
	h[0] = 1;
	rep(i, 1, N-5) {
		h[i] = h[i - 1] * base;
	}

	s[0] = ' ';
	
	while(1) {
		n = 0;
		ch = gt();
		if(ch == '.') return 0;
		while(ch != '
') {
			s[++n] = ch;
			ch = gt();
		}
		s[n + 1] = '';
		hash[0] = 0;
		rep(i, 1, n) {
			hash[i] = hash[i - 1] * base + s[i];
		}
		rep(i, 1, n) {
			if(n % i) continue;
			if(check(i,H(1,1+i-1))) {
				out(n/i, '
');
				break;
			}
		}
	}
	return 0;
}