求道C++题目,从键盘输入求第2大数,怎么编译?

三个数更简单！
//---------------------------------------------------------------------------
#include <iostream>

using namespace std;
int main(void)
{
int a,b,t;
cin>>a>>b>>t;
if (a<=b&&a>=t||a>=b&&a<=t) {
cout<<a<<endl;
}
else if (b<=a&&b>=t||b>=a&&b<=t) {
cout<<b<<endl ;
}
else cout<<t<<endl;

return 0;
}
//---------------------------------------------------------------------------

至少输入2个数字，整数之间用空格或者回车分隔，用CTRL+Z结束输入

//---------------------------------------------------------------------------
#include <iostream>

using namespace std;
int main(void)
{
int a,b,t;
cin>>a>>b;
if (a<b) {
t=a;
a=b;
b=t;
}
while (cin>>t)
{

if (t>b&&t<a) {
b=