//1.17//遍历数组a，计算其中负数的个数int amount=0;for(int i=0;i<strlen(a);i++)    if(a[i]<0)        ++amount;

//1.19//每隔输10个值for(int val=lower,count=1;val<=upper;++val,++count){    cout<<val<<" ";    if(count%10==0)        cout<<endl;}