
ZOJ Problem Set  2814
The Dpairs of a string of letters are the ordered pairs of letters that are distance D from each other. A string is Dunique if all of its Dpairs are different. A string is surprising if it is Dunique for every possible distance D. Consider the string ZGBG. Its 0pairs are ZG, GB, and BG. Since these three pairs are all different, ZGBG is 0unique. Similarly, the 1pairs of ZGBG are ZB and GG, and since these two pairs are different, ZGBG is 1unique. Finally, the only 2pair of ZGBG is ZG, so ZGBG is 2unique. Thus ZGBG is surprising. (Note that the fact that ZG is both a 0pair and a 2pair of ZGBG is irrelevant, because 0 and 2 are different distances.) Input: The input consists of one or more nonempty strings of at most 79 uppercase letters, each string on a line by itself, followed by a line containing only an asterisk that signals the end of the input. Output: For each string of letters, output whether or not it is surprising using the exact output format shown below. Acknowledgement: This problem is inspired by the "Puzzling Adventures" column in the December 2003 issue of Scientific American.
Source: MidCentral USA 2006 