BISHI59 阶乘末尾非零数字

思路

求解代码

publicstaticvoidmain(String[]args)throwsIOException{BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));StreamTokenizerin=newStreamTokenizer(br);PrintWriterout=newPrintWriter(newOutputStreamWriter(System.out));in.nextToken();intn=(int)in.nval;out.println(find(n));out.flush();out.close();br.close();}privatestaticintfind(intn){intn2=0,n5=0;intp=1;for(inti=2;i<=n;i++){inttmp=i;while(tmp%5==0){n5++;tmp/=5;}while(tmp%2==0){n2++;tmp/=2;}p=(p*tmp)%10;}for(inti=0;i<n2-n5;i++){p=(p*2)%10;}returnp;}