exercism/rust/assembly-line

Assembly Line

Welcome to Assembly Line on Exercism's Rust Track. If you need help running the tests or submitting your code, check out HELP.md. If you get stuck on the exercise, check out HINTS.md, but try and solve it without using those first :)

Introduction

numbers

There are two different categories of numbers in Rust.

The name of a numeric type consists of two parts:

• A letter to specify whether it's a floating-point number (f), unsigned integer (u) or signed integer (i)
• A number to specify the numbers size in bits. Larger types have a greater range between minimum and maximum values. For floating points it will also allow for more numbers behind the decimal separator.

The following combinations are possible:

• 8 bits: u8, i8
• 16 bits: u16, i16
• 32 bits: u32, i32, f32
• 64 bits: u64, i64, f64
• 128 bits: u128, i128

Note that there are only 32-bits and 64-bits variants for floating-point numbers.

Integers

• Integers: numbers with no digits behind the decimal separator (whole numbers). Integer types can either store only positive numbers (unsigned) or store either positive and negative numbers (signed). Examples are -6, 0, 1, 25, 976 and 500000.

Floating Point Numbers

• Floating-point numbers: numbers with zero or more digits behind the decimal separator. Examples are -2.4, 0.1, 3.14, 16.984025 and 1024.0.

Converting between number types

Rust doesn't do any implicit type conversion. This means that if you need to turn one numeric type into another, you have to do so explicitly. When converting from a larger type to a smaller one (for instance u64 to u32) you could lose data. Converting from a floating point to an integer will lose everything behind the decimal point, effectively rounding down.

Instructions

In this exercise you'll be writing code to analyze the production of an assembly line in a car factory. The assembly line's speed can range from 0 (off) to 10 (maximum).

At its lowest speed (1), 221 cars are produced each hour. The production increases linearly with the speed. So with the speed set to 4, it should produce 4 * 221 = 884 cars per hour. However, higher speeds increase the likelihood that faulty cars are produced, which then have to be discarded. The following table shows how speed influences the success rate:

• 1 to 4: 100% success rate.
• 5 to 8: 90% success rate.
• 9 and 10: 77% success rate.

You have two tasks.

1. Calculate the production rate per hour

Implement a method to calculate the assembly line's production rate per hour, taking into account its success rate:

numbers::production_rate_per_hour(6)
// Returns: 1193.4

Note that the value returned is an f64.

2. Calculate the number of working items produced per minute

Implement a method to calculate how many working cars are produced per minute:

numbers::working_items_per_minute(6)
// Returns: 19

Note that the value returned is an u32.

Source

Created by

• @LewisClement
• @efx