题解 | #挑7#
挑7
https://www.nowcoder.com/practice/ba241b85371c409ea01ac0aa1a8d957b
#include <iostream> using namespace std; int main() { int n; cin>>n; int count = 0; for(int i = 1;i!=n+1;++i) { string s = to_string(i); bool flag = true; for(auto i:s) { if(i=='7') { ++count; flag = false; break; } } if(flag) { if(i%7==0) ++count; } } cout<<count; } // 64 位输出请用 printf("%lld")
字符串处理某个数字的某一位非常的方便