add ex52 slices

1 files changed, 49 insertions, 0 deletions

diff --git a/exercises/52_slices.zig b/exercises/52_slices.zig
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+//
+// We've seen that passing arrays around can be awkward. Perhaps you
+// remember a particularly horrendous function definition from quiz3?
+// This function can only take arrays that are exactly 4 items long!
+//
+//     fn printPowersOfTwo(numbers: [4]u16) void { ... }
+//
+// That's the trouble with arrays - their size is part of the data
+// type and must be hard-coded into every usage of that type. This
+// digits array is a [10]u8 forever and ever:
+//
+//     var digits = [10]u8{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
+//
+// Thankfully, Zig has slices, which let you dynamically point to a
+// start item and provide a length. Here are slices of our digit
+// array:
+//
+//     const foo = digits[0..1];  // 0
+//     const bar = digits[3..9];  // 3 4 5 6 7 8
+//     const all = digits[0..];   // 0 1 2 3 4 5 6 7 8 9
+//
+// As you can see, a slice [x..y] defines a first item by index x and
+// a length y (where y-1 is the index of the last item). Leaving y off
+// gives you the rest of the items.
+//
+// Notice that the type of a slice on an array of u8 items is []u8.
+//
+const std = @import("std");
+
+pub fn main() void {
+    var cards = [8]u8{ 'A', '4', 'K', '8', '5', '2', 'Q', 'J' };
+
+    // Please put the first 4 cards in hand1 and the rest in hand2.
+    const hand1: []u8 = cards[???];
+    const hand2: []u8 = cards[???];
+
+    std.debug.print("Hand1: ", .{});
+    printHand(hand1);
+
+    std.debug.print("Hand2: ", .{});
+    printHand(hand2);
+}
+
+// Please lend this function a hand. A u8 slice hand, that is.
+fn printHand(hand: ???) void {
+    for (hand) |h| {
+        std.debug.print("{u} ", .{h});
+    }
+}