51NOD 1413 powerful binary (thinking)

Portal

A decimal integer is called the Power binary, when his decimal representation is made up of only 0 or 1. For example, 0,1,101,110011 are powerful binaries and 2,12,900 not.
When given an n, calculate the minimum number of powerful binary additions to get N.

Input
A single set of test data.
The first line gives an integer n (1<=n<=1,000,000)
Output
One row for the output answer.
Input example
9
Output example
9

Problem Solving Ideas:
This topic, in fact, the problem is to find the largest number of all digits, this is difficult to think of. As an example:
9998 can be obtained by 8 of 1111 and one 1110:
5656 can be obtained by 5 of 1111 and one 101
5678 can be obtained by 5 1111 and one 111 and one 11 and one 1
So it is to ask for a maximum value of 10 for each bit.

My Code:

 #include <iostream>   #include <cstdio>  using  Span class= "Hljs-keyword" >namespace  STD ;    int  Main () {int  N; scanf     ( "%d" , &n);    int  ans = 0 ; while         (n) {int  m = N%10 ; if         (Ans < m) ans = m;    n/= 10 ;    } cout  <<ans<<endl; return  0 ;}  

51NOD 1413 Powerful binary (thinking)