统计1到n中1的出现个数

例如1到12中一出现了5次：1,10,11,12

#include<iostream>
using namespace std;
int numof1(int n){  
    int m = 0;  
    while(n){  
        m +=((n % 10 == 1)?1:0); 
        n = n / 10;  
    }  
    return m;  
}  
int main()  
{   int n,i,count;
    cout<<"please put in the num"<<endl;  
    cin>>n;
    if( n!= 0){  
        count = 0;  
        for(i = 1;i <= n;i++){  
            count += numof1(i);  
        }  
        cout<<"the number of 1 is"<<count<<endl;  
    }  
    return 0;  
}