LA3026 POJ1961 period 字符串周期(KMP) POJ2406 Power Strings
POJ1961http://poj.org/problem?id=1961PeriodDescriptionForeachprefixofagivenstringSwithNcharacters(eachcharacterhasanASCIIcodebetween97and126,inclusive),wewanttoknowwhethertheprefixisaperiodicstring.Th