CSE 109   Test 2    Wednesday  29 November 2006
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1. Consider the abstract data type of an ordered pair and label the elements
of the pair x and y.  We should be able to create an ordered pair, get the
entries in the pair, and print it out.  Write the template for the OrdPair
class so that the following code will compile and produce the indicated
output.
   OrdPair<int,double> a(7,3.2);
   cout<<a.getX()<<" "<<a.getY()<<" "<<a<<endl; // 7 3.2 (7, 3.2)
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#include <iostream>
using namespace std;
template <class A, class B>
class OrdPair
{public:
  OrdPair(const A &a, const B &b);
  A getX()const;
  B getY()const;
 template <class X, class Y>
 friend ostream & operator<<(ostream &out,const OrdPair<X,Y> & op);
 private:
   A x;
   B y;
};

template <class A, class B>
OrdPair<A,B>::OrdPair(const A&a, const B&b):x(a), y(b){}

template <class A, class B>
A OrdPair<A,B>::getX()const{return x;}

template <class A, class B>
B OrdPair<A,B>::getY()const {return y;}

 template <class X, class Y>
 ostream & operator<<(ostream &out,const OrdPair<X,Y> & op)
 {out<<"("<<op.x<<", "<<op.y<<")";
  return out;}
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2.  Write a program that takes two and only two command line arguments,
the names of two input files of text, and displays on the screen the contents
of the first file, followed by the contents of the second file.  If the
executable code for the program is stored in a.out, the call takes the form
    a.out inputFile1 inputFile2
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#include <fstream>
#include <iostream>
using namespace std;
void check(bool b,char *mess)
{if(!b)
  {cerr<<"ERROR: "<<mess<<endl;
   exit(1);
  }
}
void dump(istream & in)
{char ch;
 ch=in.get();
 while(in.good())
  {cout<<ch;
   ch=in.get();
  }
}
int main(int ct,char**arg)
{check(ct==3,"Usage: a.out <file1> <file2>");
 ifstream fila(arg[1]),filb(arg[2]);
 check(fila.good() && filb.good(), "Bad input file");
 dump(fila);
 dump(filb);
}
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3.  Assume that the class BiNode below is used to construct binary trees.
Write a function, div3(), that returns the number of entries in the tree that
are divisible by 3.  If we have  BiNode *head; then the call to div3() would
be div3(head).
    class BiNode
    {public:
      int data;
      BiNode *left,*right;
    };
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int div3(BiNode *rt)
{int temp;
 if(rt==NULL)
     return 0;
 else
  {if(rt->data%3==0)
    temp=1;
   else
    temp=0;
   return temp+div3(rt->left)+div3(rt->right);
  }
}
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4.  Write both an ASM++ program and a MACH1 program that reads in a number
and prints out 1 if it is between 1 and 10 inclusive and prints 0 otherwise.
Recall the MACH1 operations   READ(0), WRITE(1), LOAD(2), STORE(3), CLEAR(4),
ADD(5), SUB(6), MUL(7), DIV(8), ADDIMMED(9), SUBIMMED(10), MULIMMED(11),
DIVIMMED(12), JUMPLE(13), JUMPGE(14) HALT(15)
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    read x
    jump (x<1) 100
    jump (x>10) 100
    write 1
    halt
100 write 0
    halt
    end

    0 0                  [0]
    13 8   jump if x<=0  [1]
    10 11                [2]
    14 8   jump if x>=11 [3]
    4  0                 [4]
    9  1                 [5]
    1 0     write 1      [6]
    15 0                 [7]
    4 0                  [8]
    1 0     write 0      [9]
    15 0                [10]
    E
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