#include <string> #include <iostream> class Solution { public: int NumberOf1Between1AndN_Solution(int n) { int count = 0; for(int i = 1; i <= n; i++){ string number = to_string(i); count += std::count(number.begin(),number.end(),'1'); } return count; } }; 我的思路简单粗暴,将每一个数字转成字符串,然后统计这个字符...