CECS342 Homework 1: Imperator Furiosharp Solved

Complete both of the programs below in F#.

Program 1: Someone Set Up Us the Bomb
Program a simple text-based game in which the player attempts to shoot cannonballs at a target that is some distance away. The player repeatedly enters an angle to re the cannon at and an amount of gunpowder to use. The game calculates how far the cannonball will y under those parameters and continues until the cannonball falls within 1 meter of the target. Program the game in this way:

1.   A function placeTarget, which takes no parameters and returns a random oat value between 0 and 1000 meters, inclusive. Review how to declare a function that takes no parameters. Use (new Random()).NextDouble() to generate a random oat from 0.0 to 1.0. The return value represents the distance at which the target is placed at the start of the game.

2.   A function getAngle, which takes no parameters and prompts the user to enter an angle to re the cannon at. An angle must be between 0 and 90 degrees. Read a line of text from the console and convert it to a oat. Repeatedly ask for an angle (in a loop) until a valid angle is entered. Return the angle.

3.   A function getGunpowder, which takes no parameters and prompts the user to enter a positive oat for the amount of gunpowder to use when ring the cannon. Return the amount.

4.   A function calculateDistance, which takes an angle and an amount of gunpowder, and returns the total horizontal distance that a projectile red at the given angle will y. The angle is in degrees; the gunpowder amount is in kilograms, and each kilogram of gunpowder results in 30 meters/second of initial velocity. You will nd Math.Sin and Math.Cos useful, but note that they operate on radians, not degrees. Use 9.81 m/s2 for acceleration due to gravity.

5.   A function isHit, which takes the location of the target and the distance that the cannonball res, and returns true if and only if the cannonball falls within 1.0 meter of the target. Do not use any let statements in this function.

6.   A main function that plays the game:

(a)    Generate a target distance. Print the distance to the user.

(b)    Get the angle and the gunpowder.

(c)     Calculate the distance the ball travels.

(d)    If it’s a hit, print a message and terminate. Otherwise, print how far away from the target thecannonball landed (indicate short or long if the ball did not travel far enough / traveled too far, respectively), and repeat steps (b) through (d).

(e)    Note: F# does not have a break statement or a way to return early from a function.

Program 2: Project Euler
Solve Problem 10 on ProjectEuler.net using the F# programming language. Do not look up an answer and copy it. You must solve the problem by structuring your code this way:

1.   A function isPrime, which takes a single argument n and returns true if the argument is a prime number. (Hint: starting with i =2, determine if i is a factor of n. Check the next value of i if it is not. Stop when you reach the largest value of i that could be a factor of n, recognizing that all of n’s

1

factors j have another integer j∗ that forms a factor pair with j, so that if you have already checked j to see if it is a factor of n, you don’t have to also check j∗, particularly if it is larger than j...)

2.   A function sumPrimes, which takes a single argument max and returns the sum of all prime numbers up to max, inclusive. Use imperative-style programming for this function: declare a sum variable, iterate a while loop from 3 up to max increasing by ____ ( ll in the blank), check to see if each value in the iteration isPrime, and if it is, mutate the sum. Don’t forget to account for the number 2 being prime. Break when you reach max.

3.   A main function that solves the problem.