4指出下列程序的错误。 #include <iostream.h> void exchange(int&, int&); void maino (cout<< Input two data seprated by space: " Int a, b: cin>>a>>b cout<< Before Exchange: a=w<<a<<b="<<b<<endl exchange(a, b) cout<<After Exchange: a=<<a<<,b=<<b<<endl void exchange(int &x, int &y) Rint t; t-x;x-y;y=t 9C++程序设计课件 设计制作：徐龙琴 9 4 指出下列程序的错误。 #include <iostream.h> void exchange(int,int); void main() {cout<<"Input two data seprated by space:"; int a,b; cin>>a>>b; cout<<"Before Exchange:a="<<a <<",b="<<b<<endl; exchange(a,b); cout<<"After Exchange:a= "<<a <<",b="<<b<<endl; } void exchange(int x,int y) { int t; t=x;x=y;y=t; } #include <iostream.h> void exchange(int*,int*); void main() {cout<<"Input two data seprated by space:"; int a,b,*p1=&a,*p2=&b; cin>>a>>b; cout<<"Before Exchange:a="<<a<<",b="<<b<<endl; exchange(p1,p2); cout<<"After Exchange:a="<<a<<",b="<<b<<endl; } void exchange(int *x,int *y) { int t; t=*x;*x=*y;*y=t; } #include <iostream.h> void exchange(int&,int&); void main() {cout<<"Input two data seprated by space:"; int a,b; cin>>a>>b; cout<<"Before Exchange:a="<<a<<",b="<<b<<endl; exchange(a,b); cout<<"After Exchange:a="<<a<<",b="<<b<<endl; } void exchange(int &x,int &y) {int t; t=x;x=y;y=t; }