题解 | #挑7#
挑7
https://www.nowcoder.com/practice/ba241b85371c409ea01ac0aa1a8d957b
#include <iostream>
using namespace std;
bool find7(int n){
if(n%7==0)return true;
while(n){
if(n%10==7)return true;
n = n/10;
}
return false;
}
int ans(int n){
int res=0;
for(int i=7; i<=n;i++){
if(find7(i))res++;
}
return res;
}
int main() {
int n;
cin>>n;
cout<<ans(n);
}
// 64 位输出请用 printf("%lld")
