题解 | #挑7#

#include <stdio.h>

int main() {
    int n,count=0;
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        int temp = i;
        if(temp%7==0){
            count++;
            continue;
        }
        else{
            int num = 0;
            while(temp>0){
                num= temp%10;
                if(num==7){
                    count++;
                    break;
                }
                temp /=10;
            }
            continue;
        }
    }
    printf("%d",count);
    return 0;
}