无标题.jpg

#include <stdio.h>

int main(){
    int N;
    int sum;    //保存幻数和 
    int shuzi;
    int i;
    
    scanf("%d", &N);
    
    for (i=1;i<=N;i++){
        if (i % 7 == 0) {
            sum += i;
            printf("%d ", i);
        }           
        else {
            shuzi = i;
            while (shuzi>10){
                if (shuzi % 10 == 7){
                    sum += shuzi;
                    printf("%d ", shuzi);
                    break;
                }
                shuzi = shuzi / 10;
            }
        }
    }
    printf("\n从1到%d的幻数之和：%d", N, sum);
}