/in/foo.cc: In function 'void Merge(int*, int, int*, int)':
/in/foo.cc:16:20: error: expected primary-expression before '<' token
    for(int i=0,j=0;<a[i]!=0 || b[j]!=0;i++,j++)
                    ^
/in/foo.cc:36:11: error: 'c' was not declared in this scope
     cout<<c[i]<<endl;
           ^
/in/foo.cc:14:6: warning: unused variable 'i' [-Wunused-variable]
  int i,k=0;
      ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:60:3: error: 'a1' was not declared in this scope
   a1[i] = num;
   ^~
/in/foo.cc:65:3: error: 'a2' was not declared in this scope
   a2[i] = num;
   ^~
/in/foo.cc:70:3: error: 'a3' was not declared in this scope
   a3[i] = num;
   ^~
/in/foo.cc:74:14: error: 'a1' was not declared in this scope
     s.Merge (a1,n1,a2,n2);
              ^~
/in/foo.cc:74:20: error: 'a2' was not declared in this scope
     s.Merge (a1,n1,a2,n2);
                    ^~
/in/foo.cc:75:17: error: 'a3' was not declared in this scope
  s.Merge (a1,n1,a3,n3);
                 ^~
/in/foo.cc:56:6: warning: unused variable 'a' [-Wunused-variable]
  int a[100], b[100],c[100];
      ^
/in/foo.cc:56:14: warning: unused variable 'b' [-Wunused-variable]
  int a[100], b[100],c[100];
              ^
/in/foo.cc:56:21: warning: unused variable 'c' [-Wunused-variable]
  int a[100], b[100],c[100];
                     ^