题解 | #挑7#
挑7
https://www.nowcoder.com/practice/ba241b85371c409ea01ac0aa1a8d957b
#include <iostream>
#include <string>
using namespace std;
int main() {
string str;
int num,cnt = 0;
cin >> num;
for (int i = 7; i <= num; ++i)
{
if (i % 7 == 0)
{
cnt++;
continue;
}
str = to_string(i);
for (char x : str)
{
if (x == '7')
{
cnt++;
break;
}
}
}
cout << cnt << endl;
return 0;
}
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