CSCI 255 — Programming Expectations

This lab gives an example of the programming expertise needed for this course.

Getting started

Start up NetBeans and create a project for a Java Application. Use the names of your choice.

Delete the default main method and replace it with the following:

    public static void main(String[] args) {
        java.util.Random g = new java.util.Random() ;
        int X[] = new int[1000 + g.nextInt(10)] ;
        for (int i = 0; i<X.length; ++i) {
            X[i] = g.nextInt(10) ;
        }
        System.out.println(exceeds(X, 3)) ;
        System.out.println(exceeds(X, 7)) ;
        System.out.println(exceeds(new int[]{}, 2015)) ;
     }

Writing the missing method

This program is missing the exceeds method. A correct exceeds method takes two arguments. The first is an array of integers, and the second is an integer. The exceeds method returns the number of elements in the array that are greater than the second argument.

When run, this problem should print three numbers. The first should be close to 600, the second should be close to 200, and the third should be 0.

For those who prefer an alternative

Here are some alternate entry points for those with more experience with C, C++, Python, or Processing.

Processing

Because Processing is an extension of Java, the implementation of exceeds is the same as in Java (ignoring the public static method modifier required in Java). If you want to use the Processing IDE, start with the following program and add exceeds.

void setup() {
  noLoop() ;
}

void draw()
{
  java.util.Random g = new java.util.Random() ;
  int X[] = new int[1000 + g.nextInt(10)] ;
  for (int i = 0; i<X.length; ++i) {
    X[i] = g.nextInt(10) ;
   }
   println(exceeds(X, 3)) ;
   println(exceeds(X, 7)) ;
   println(exceeds(new int[]{}, 2015)) ;
}

C

Start with the following main routine. Because C and C++ don’t have an operator for determining the size of an array, the exceeds function requires an additional argument that gives the size of the array.

    #include <time.h>
    #include <stdio.h>
    #include <stdlib.h>

    int main(int argc, char** argv) {
      int X[1010], xSize, i ;
      srand(time(NULL)) ;
      xSize = 1000 + rand()%10 ;
      for (i = 0; i<xSize; ++i) {
        X[i] = rand()%10 ;
      }
      fprintf(stdout, "%d\n", exceeds(X, xSize, 3)) ;
      fprintf(stdout, "%d\n", exceeds(X, xSize, 7)) ;
      fprintf(stdout, "%d\n", exceeds(X, 0, 2015)) ;
      return (EXIT_SUCCESS);
    }

Python

Start with the following Python program and add the exceeds function. This program uses the common Python list rather than the much rarer (and more difficult) array class.

import random

def main():
    g = random.Random()
    x = [g.randint(0, 9) for e in range(g.randint(1000, 1009))]
    print(exceeds(x, 3))
    print(exceeds(x, 7))
    print(exceeds([], 2015))

if __name__ == "__main__":
    main()