Added Quiz 5 for pointers. Elephants!!!

This commit is contained in:
Dave Gauer 2021-02-09 20:15:09 -05:00
parent 55ad7c32f2
commit 961cf22b88
3 changed files with 47 additions and 2 deletions

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@ -44,7 +44,7 @@ const Class = enum{
const Character = struct{
class: Class,
gold: u32,
health: u8,
health: u8 = 100, // <--- You can also fields a default value!
experience: u32,
};
@ -52,7 +52,6 @@ pub fn main() void {
var glorp = Character{
.class = Class.wizard,
.gold = 10,
.health = 100,
.experience = 20,
};

45
exercises/44_quiz5.zig Normal file
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@ -0,0 +1,45 @@
//
// "Elephants walking
// Along the trails
//
// Are holding hands
// By holding tails."
//
// from Holding Hands
// by Lenore M. Link
//
const std = @import("std"); // single quotes
const Elephant = struct{
letter: u8,
tail: *Elephant = undefined,
visited: bool = false,
};
pub fn main() void {
var elephantA = Elephant{ .letter = 'A' };
// (Please add Elephant B here!)
var elephantC = Elephant{ .letter = 'C' };
// Link the elephants so that each tail "points" to the next elephant.
// They make a circle: A->B->C->A...
elephantA.tail = &elephantB;
// (Please link Elephant B's tail to Elephant C here!)
elephantC.tail = &elephantA;
visitElephants(&elephantA);
}
// This function visits all elephants once, starting with the
// first elephant and following the tails to the next elephant.
// If we did not "mark" the elephants as visited (by setting
// visited=true), then this would loop infinitely!
fn visitElephants(first_elephant: *Elephant) void {
var e = first_elephant;
while (!e.visited) {
std.debug.print("Elephant {u}. ", .{e.letter});
e.visited = true;
e = e.tail;
}
}

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@ -115,6 +115,7 @@ check_it 40_pointers2.zig "a: 12, b: 12"
check_it 41_pointers3.zig "foo=6, bar=11"
check_it 42_pointers4.zig "num: 5, more_nums: 1 1 5 1"
check_it 43_pointers5.zig "Wizard (G:10 H:100 XP:20)"
check_it 44_quiz5.zig "Elephant A. Elephant B. Elephant C." "Oh no! We forgot Elephant B!"
echo
echo " __ __ _ "