UVA455Periodic Strings(最小周期串)

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.A character string is said to have period k if