题解 | 整数中1出现的次数（从1到n整数中1出现的次数）

class Solution {
public:
    int count_1(int v)
    {
        int count=0;
        while(v)
        {
            if(v%10==1)
            {
                count++;
            }
            v/=10;
        }
        return count;
    }
    int NumberOf1Between1AndN_Solution(int n) {
        if(n==0)
        {
            return 0;
        }
        int count=0;
        for(int i=1;i<=n;i++)
        {
            count+=count_1(i);
        }
        return count;
    }
};