POJ 2406 Power Strings 笔记
定义字符串乘为：例如a = "abc" ，b = "def" a*b = "abcdef"。定义字符串的幂：a^0 = “”， a^(n+1) = a*(a^n)。给出字符串s，满足s = a^n，求最大的n。
定义字符串乘为：例如a = "abc" ，b = "def" a*b = "abcdef"。定义字符串的幂：a^0 = “”， a^(n+1) = a*(a^n)。给出字符串s，满足s = a^n，求最大的n。