fixed removed array multiplication

This commit is contained in:
Chris Boesch
2026-05-04 17:15:30 +02:00
parent 1ba1e301a8
commit 8af3372cf2
14 changed files with 51 additions and 64 deletions

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@@ -1,5 +1,5 @@
//
// Zig has some fun array operators.
// Zig has one array operators.
//
// You can use '++' to concatenate two arrays:
//
@@ -7,12 +7,8 @@
// const b = [_]u8{ 3,4 };
// const c = a ++ b ++ [_]u8{ 5 }; // equals 1 2 3 4 5
//
// You can use '**' to repeat an array:
//
// const d = [_]u8{ 1,2,3 } ** 2; // equals 1 2 3 1 2 3
//
// Note that both '++' and '**' only operate on arrays while your
// program is _being compiled_. This special time is known in Zig
// Note that '++'' only operate on arrays while your program is
// _being compiled_. This special time is known in Zig
// parlance as "comptime" and we'll learn plenty more about that
// later.
//
@@ -30,7 +26,8 @@ pub fn main() void {
// (Problem 2)
// Please set this array using repetition.
// It should result in: 1 0 0 1 1 0 0 1 1 0 0 1
const bit_pattern = [_]u8{ ??? } ** 3;
const bit_pattern_unit = [_]u8{ ??? };
const bit_pattern: [3 * bit_pattern_unit.len]u8 = @bitCast(@as([3][bit_pattern_unit.len]u8, @splat(bit_pattern_unit)));
// Okay, that's all of the problems. Let's see the results.
//

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@@ -27,10 +27,6 @@ pub fn main() void {
const d: u8 = ziggy[???];
// (Problem 2)
// Use the array repeat '**' operator to make "ha ha ha ".
const laugh = "ha " ???;
// (Problem 3)
// Use the array concatenation '++' operator to make "Major Tom".
// (You'll need to add a space as well!)
const major = "Major";
@@ -38,7 +34,7 @@ pub fn main() void {
const major_tom = major ??? tom;
// That's all the problems. Let's see our results:
std.debug.print("d={u} {s}{s}\n", .{ d, laugh, major_tom });
std.debug.print("d={u} {s}\n", .{ d, major_tom });
// Keen eyes will notice that we've put 'u' and 's' inside the '{}'
// placeholders in the format string above. This tells the
// print() function to format the values as a UTF-8 character and

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@@ -224,11 +224,10 @@ const NotebookEntry = struct {
// +---+----------------+----------------+----------+
//
const HermitsNotebook = struct {
// Remember the array repetition operator `**`? It is no mere
// novelty, it's also a great way to assign multiple items in an
// array without having to list them one by one. Here we use it to
// initialize an array with null values.
entries: [place_count]?NotebookEntry = .{null} ** place_count,
// Remember the array repetition function @splat()? It is a great way
// to assign multiple items in an array without having to list them
// one by one. Here we use it to initialize an array with null values.
entries: [place_count]?NotebookEntry = @splat(null),
// The next entry keeps track of where we are in our "todo" list.
next_entry: u8 = 0,
@@ -409,7 +408,7 @@ pub fn main() void {
// aside memory for the trip and have the hermit's notebook fill
// in the trip from the destination back to the path. Note that
// this is the first time we've actually used the destination!
var trip = [_]?TripItem{null} ** (place_count * 2);
var trip: [place_count * 2]?TripItem = @splat(null);
notebook.getTripTo(trip[0..], destination) catch |err| {
print("Oh no! {}\n", .{err});

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@@ -39,16 +39,16 @@ pub fn main() void {
var count = 0;
count += 1;
const a1: [count]u8 = .{'A'} ** count;
const a1: [count]u8 = @splat('A');
count += 1;
const a2: [count]u8 = .{'B'} ** count;
const a2: [count]u8 = @splat('B');
count += 1;
const a3: [count]u8 = .{'C'} ** count;
const a3: [count]u8 = @splat('C');
count += 1;
const a4: [count]u8 = .{'D'} ** count;
const a4: [count]u8 = @splat('D');
print("{s} {s} {s} {s}\n", .{ a1, a2, a3, a4 });

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@@ -32,7 +32,7 @@ fn makeCreature(comptime count: usize, comptime fmt: []const u8) [count]Animal {
// We return an array of animals representing the creature. (This is why we
// really needed the 'count' parameter. Arrays need a size.)
var animals: [count]Animal = .{undefined} ** count;
var animals: [count]Animal = undefined;
var next_animal: usize = 0;
inline for (fmt) |char| {

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@@ -48,9 +48,7 @@ const Path = struct {
// instead.
//
// Please fill in the body of this function!
fn makePath(from: *Place, to: *Place, dist: u8) Path {
}
fn makePath(from: *Place, to: *Place, dist: u8) Path {}
// Using our new function, these path definitions take up considerably less
// space in our program now!
@@ -97,7 +95,7 @@ const NotebookEntry = struct {
};
const HermitsNotebook = struct {
entries: [place_count]?NotebookEntry = .{null} ** place_count,
entries: [place_count]?NotebookEntry = @splat(null),
next_entry: u8 = 0,
end_of_entries: u8 = 0,
@@ -193,7 +191,7 @@ pub fn main() void {
}
}
var trip = [_]?TripItem{null} ** (place_count * 2);
var trip: [place_count * 2]?TripItem = @splat(null);
notebook.getTripTo(trip[0..], destination) catch |err| {
print("Oh no! {}\n", .{err});