Enter an integer n to calculate the number of times 1 appears in the decimal representation of the N integers from 1 to n.

For example, input 12, integers from 1 to 12 contain numbers 1, 10, 11, and 12, and 1 appear 5 times in total.

Public class test {// Number of all numbers from 1 to n public static int gettotal (int n) {If (n = 0) {return 0 ;} else {return gettotal (n-1) + Get (n) ;}// the first public static int get (int I) {string S = I + ""; int num = 0; For (Int J = 0; j <S. length (); j ++) {If (S. charat (j) = '1') {num ++;} return num;} public static void main (string [] ARGs) {// todo auto-generated method stubsystem. out. print (gettotal (12 ));}}