∥824 #include <iostream.h> main nt a=l #define ti a+a #define t2 t1-t1 cout<< t2 is <<T2<<endla aHI址 return U; cout<<“T2is“<<a+a-a+a<<endl ∥825 #include <iostream.h> maIn i int a=l; const Tl=a++a; const T2=T1-T1 cout<<t2 is <<T2<<endll return 0 8// 例2.4 #include <iostream.h> main( ) { int a=1; #define T1 a+a #define T2 T1 -T1 cout<<"T2 is "<<T2<<endl; return 0; } cout<<“T2 is “<<a+a -a+a<<endl; // 例2.5 #include <iostream.h> main( ) { int a=1; const T1=a+a; const T2=T1 -T1; cout<<"T2 is "<<T2<<endl; return 0; } a+ T2 a a+a T1 -T1 8