learngo/x-tba/slices/exercises/README.md

Slice Exercises

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ANNOUNCEMENT

I teach you what the other courses don't even care to teach.

What's new?

• New Section: Advanced Slice Operations
• New Exercises for the Slice Internals
• New Exercises for the Slices: Advanced Operations

What are you going to learn?

• Full Slice Expressions: Limiting access to the backing array
• Make(): Preallocation
• Copy(): Efficiently and safely copy elements without using a loop
• Multi-Dimensional Slices

What's coming next?

• Empty Filer Finder: Your first taste of file operations.
• Bouncing Ball: Create a bouncing ball animation on a 2D surface.
• Png Parser: Parse a PNG file by hand and tell its dimensions.

These lectures will be added in the next 3 weeks.

Statistics:

• +1 hour of additional content!
• +5 new lectures
• +20 new questions
• 3 + ? new exercises

Total content in the slices section:

• ? hours
• ? lectures
• ? questions
• ? exercises

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Full Slice Exp + Make + Copy + Multi-Dim Slices

FIX THIS

1. Limit the backing array sharing

• fix the excess memory allocation

  • return a huge slice from a func, ask the student fix it

• full slice exp: https://play.golang.org/p/SPrLspRBXdI

• copy: https://play.golang.org/p/SPrLspRBXdI

  • • put \n for the beatles exercise using copy

    s = append(s, 0 /* use the zero value of the element type */)
    copy(s[i+1:], s[i:])
    s[i] = x
  

• multi dim slices batches

actions := []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
batchSize := 3
var batches [][]int

for batchSize < len(actions) {
    actions, batches = actions[batchSize:], append(batches, actions[0:batchSize:batchSize])
}
batches = append(batches, actions)