"999 is enough for anybody" triple-zero padding (#18)

When I hit 999 exercises, I will finally have reached the ultimate
state of soteriological release and no more exercises will be needed.
The cycle will be complete. All that will be left is perfect quietude,
freedom, and highest happiness.

1 files changed, 43 insertions, 0 deletions

diff --git a/exercises/020_quiz3.zig b/exercises/020_quiz3.zig
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index 0000000..651af8c
--- /dev/null
+++ b/exercises/020_quiz3.zig
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+//
+// Let's see if we can make use of some of things we've learned so far.
+// We'll create two functions: one that contains a "for" loop and one
+// that contains a "while" loop.
+//
+// Both of these are simply labeled "loop" below.
+//
+const std = @import("std");
+
+pub fn main() void {
+    const my_numbers = [4]u16{ 5, 6, 7, 8 };
+
+    printPowersOfTwo(my_numbers);
+    std.debug.print("\n", .{});
+}
+
+// You won't see this every day: a function that takes an array with
+// exactly four u16 numbers. This is not how you would normally pass
+// an array to a function. We'll learn about slices and pointers in
+// a little while. For now, we're using what we know.
+//
+// This function prints, but does not return anything.
+//
+fn printPowersOfTwo(numbers: [4]u16) ??? {
+    loop (numbers) |n| {
+        std.debug.print("{} ", .{twoToThe(n)});
+    }
+}
+
+// This function bears a striking resemblance to twoToThe() in the last
+// exercise. But don't be fooled! This one does the math without the aid
+// of the standard library!
+//
+fn twoToThe(number: u16) ??? {
+    var n: u16 = 0;
+    var total: u16 = 1;
+
+    loop (n < number) : (n += 1) {
+        total *= 2;
+    }
+
+    return ???;
+}