1 files changed, 35 insertions, 0 deletions
diff --git a/aoc/2021/10/Stack.zig b/aoc/2021/10/Stack.zig
new file mode 100644
index 0000000..1aab8eb
--- /dev/null
+++ b/aoc/2021/10/Stack.zig
@@ -0,0 +1,35 @@
+const Allocator = @import("std").mem.Allocator;
+const Self = @This();
+
+allocator: *Allocator,
+memory: []u8,
+len: usize,
+
+pub fn alloc(allocator: *Allocator, size: usize) !Self {
+    return Self{
+        .allocator = allocator,
+        .memory = try allocator.alloc(u8, size),
+        .len = 0,
+    };
+}
+
+pub fn free(self: *Self) void {
+    self.allocator.free(self.memory);
+    self.* = undefined;
+}
+
+pub fn push(self: *Self, node: u8) void {
+    self.memory[self.len] = node;
+    self.len += 1;
+}
+
+pub fn pop(self: *Self) ?u8 {
+    if (self.len < 1)
+        return null;
+    self.len -= 1;
+    return self.memory[self.len];
+}
+
+pub fn reset(self: *Self) void {
+    self.len = 0;
+}