s=a+aa+aaa+aaaa+aa...aaaa时间:2023-03-09 01:10:03 main(){ int a,n,count=1; long int sn=0,tn=0; cout<<"input a and n:"; cin>>a>>n; while(count<=n){ tn=tn+a; sn=sn+tn; a=a*10; ++count;} cout<<"a+aa+aaa+a........"<<sn;