CS211 - Algorithms and Data Structures II

Department of Computer Science, NUIM



T Naughton, NUIM

Lab Exam 1



Problem 1A.1



#include<iostream>



void main(void){



  int n;     // integer read in

  int line;  // counter for lines

  int count; // counter for blanks and 'a's



  cout << "Please enter a nonnegative integer:" << endl;

  cin >> n;



  cout << endl << "Here we go:" << endl;



  line = 0;

  while (line < n){



    count = 0;

    while (count < line){

      cout << ' ';

      count++;

    }

    count = 0;

    while (count < (line+1)){

      cout << 'a';

      count++;

    }

    cout << endl;



    line++;

  }



  cout << "Goodbye!" << endl;



}





Problem 1B.1



#include<iostream>



void main(void){



  int n;     // integer read in

  int line;  // counter for lines

  int count; // counter for blanks and '*'s



  cout << "Please enter a nonnegative integer:" << endl;

  cin >> n;



  cout << endl << "Here we go:" << endl;



  line = 0;

  while (line < n){



    count = 0;

    while (count < line){

      cout << ' ';

      count++;

    }

    count = 0;

    while (count < (n-line)){

      cout << '*';

      count++;

    }

    cout << endl;



    line++;

  }



  cout << "Goodbye!" << endl;



}





Problem 1.2



One possible answer:



int * p = NULL;  //Create a pointer called p that points to an integer

int a = 42;      //Create an integer x

p = &a;          //Assign to the pointer p the address of integer x

cout << *p;      //Output the contents of the address pointed to by p





Another example:



int * p = NULL;

int a = 42;

p = &a;

*p = 43;         //Overwrite the contents of the address pointed to by p with 43

cout << a;       //Output contents of the address pointed to by p (i.e. variable a).









Problem 1.3



#include<iostream>



void main(void){



  int iarray[10];

  double darray[10];

  int counter;



  cout << endl;

  cout << "Hi! Please enter 10 integers, one on each line:";

  cout << endl;

  counter = 0;

  while (counter < 10) {

    cin >> iarray[counter];

    counter = counter + 1;

  }

  cout << "Thanks." << endl;



  counter = 0;

  while (counter < 10) {

    darray[counter] = double(iarray[counter]) / 2.0;

    counter = counter + 1;

  }



  counter = 0;

  while (counter < 10) {

    cout << iarray[counter] << "\t";

    cout << darray[counter] << endl;

    counter = counter + 1;

  }



}