求字典序在s1和s2之间的,长度在len1到len2的字符串的个数,结果mod 1000007。
public class Main { public static long get(String a,String b,intmin) { long suma=0; long sumb=0; char[] ar=a.toCharArray(); char[] br=b.toCharArray(); for(inti=0;i<ar.length;i++) { suma=suma+(ar[i]-'a')*(long)Math.pow(26,min-1-i); } if(ar.length!=0) { suma++; } for(inti=0;i<br.length;i++) { sumb=sumb+(br[i]-'a')*(long)Math.pow(26,min-1-i); } if(br.length!=0) { sumb++; } returnsumb-suma; } publicstaticvoidmain(String[] args) { Scanner scan=newScanner(System.in); while(scan.hasNext()) { String s=scan.nextLine(); String[] array=s.split(" "); intmin=Integer.parseInt(array[2]); intmax=Integer.parseInt(array[3]); longsum=0; for(inti=min;i<=max;i++) { chara=array[0].charAt(0); charb=array[1].charAt(0); sum=sum+(long)Math.pow(26,i-1)*(b-a); String la=array[0].substring(1, i < array[0].length() ? i : array[0].length()); String lb=array[1].substring(1, i < array[1].length() ? i : array[1].length()); sum=sum+get(la,lb,i-1); } longres=sum-1; System.out.println(res%1000007); } } }