大家准备

double x,y;
cout<<"输入x=";
cin>>x;
if(x<1)
y=x;
else if(x>=1&&x<=10)
y=2*x-1;
else y=3*x-11;
cout<<"y="<<y<<endl;

cout<<"从键盘输入一组非0整数，以输入0标志结束:"<<endl;
int pnum=0,nnum=0,num,sum=0;
double average;
while(1)
{
cin>>num;
if(num>0)
pnum++;
else if(num<0)
nnum++;
else
break;
sum+=num;
}
average=sum*1.0/(pnum+nnum);
cout<<"平均值＝"<<average<<endl; //average代表平均值
cout<<"正数个数＝"<<pnum<<endl; //pnum代表正数个数
cout<<"负数个数＝"<<nnum<<endl; //nnum代表负数个数

int len = 9;
int val_1, val_2;
cin >> val_1;
cin >> val_2;
int dec_1, dec_2;
int tmp;
int cnt=0;
for ( int i=0; i<len; i++ ) {
dec_1 = pow( 10, i+1 );
dec_2 = pow( 10, i );
tmp = ( val_1 % dec_1 - val_1 % dec_2 ) / dec_2;
if ( tmp == val_2 ) cnt++;
if ( val_1 == val_1%dec_1 ) break;
}
cout << val_1 << "中" <<val_2<< "的个数为" << cnt<<endl;
/********** End **********/