#include<stdio.h>
int main(){
    int T,L,R,i,s,count,count_1=0,m;
    scanf("%d",&T);
    while(T--){
         count_1=0;   
         scanf("%d%d",&L,&R);
        for(i=L;i<=R;i++){
             m=i;
             count=0;
            while(m){
                   s=m%10;
                   if(s!=7) {
                     m=m/10;
                        count=count+s;}  
                   else break;}
        if((count%7!=0)&&(i%7!=0))
            count_1=count_1+i*i;   
        }
        printf("%d\n",count_1);
       }
}

以上程序超时，求优化

建立树吧，然后遍历