day 1

01/src/main.zig

@@ -0,0 +1,106 @@
+// Okay! First time using zig!
+// The compiler warnings are worse than C's.
+// But whatever, I'm starting to get used to some of it?
+// I think?
+// Still nowhere near idiomatic, sure I'm missing lots of better ways
+// But hey! It worked
+
+const std = @import("std");
+
+var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
+const alloc = arena.allocator();
+
+const test_data = @embedFile("test");
+const input_data = @embedFile("input");
+
+pub fn main() !void {
+    const stdout = std.io.getStdOut().writer();
+
+    const value1 = try run1(input_data);
+    try stdout.print("{d}\n", .{value1});
+
+    const value2 = try run2(input_data);
+    try stdout.print("{d}\n", .{value2});
+}
+
+test "test input part 2" {
+    const value = try run2(test_data);
+    std.debug.print("{d}\n", .{value});
+    try std.testing.expectEqual(value, 31);
+}
+
+test "test input part 1" {
+    const value = try run1(test_data);
+    std.debug.print("{d}\n", .{value});
+    try std.testing.expectEqual(value, 11);
+}
+
+fn run2(s: []const u8) !i64 {
+    var arrs = [_]std.ArrayList(i64){ std.ArrayList(i64).init(alloc), std.ArrayList(i64).init(alloc) };
+
+    var lines = std.mem.splitScalar(u8, s, '\n');
+    while (lines.next()) |line| {
+        std.debug.print("{s}\n", .{line});
+        var split = std.mem.splitScalar(u8, line, ' ');
+        var c: u8 = 0;
+        while (split.next()) |i| {
+            // idk how to put this inside the while
+            if (c >= 2) break;
+            if (std.mem.eql(u8, i, "")) continue;
+            const num = try std.fmt.parseInt(i64, i, 10);
+            try arrs[c].append(num);
+            c += 1;
+        }
+    }
+
+    // this is a lot of recalc, but these lists aren't that long so whatever
+    // i think it's O(n) so good enough
+    var sim_score: i64 = 0;
+    for (arrs[0].items) |x| {
+        for (arrs[1].items) |y| {
+            if (x == y) {
+                sim_score += x;
+            }
+        }
+    }
+
+    return sim_score;
+}
+
+fn run1(s: []const u8) !u64 {
+    var arrs = [_]std.ArrayList(i64){ std.ArrayList(i64).init(alloc), std.ArrayList(i64).init(alloc) };
+
+    var lines = std.mem.splitScalar(u8, s, '\n');
+    while (lines.next()) |line| {
+        std.debug.print("{s}\n", .{line});
+        var split = std.mem.splitScalar(u8, line, ' ');
+        var c: u8 = 0;
+        while (split.next()) |i| {
+            // idk how to put this inside the while
+            if (c >= 2) break;
+            if (std.mem.eql(u8, i, "")) continue;
+            const num = try std.fmt.parseInt(i64, i, 10);
+            try arrs[c].append(num);
+            c += 1;
+        }
+    }
+
+    for (arrs) |arr| {
+        std.mem.sort(i64, arr.items, {}, comptime std.sort.asc(i64));
+    }
+
+    for (arrs) |arr| {
+        for (arr.items) |e| {
+            std.debug.print("{d} ", .{e});
+        }
+        std.debug.print("\n", .{});
+    }
+
+    var total_dist: u64 = 0;
+    const len = arrs[0].items.len;
+    for (0..len) |i| {
+        total_dist += @abs(arrs[0].items[i] - arrs[1].items[i]);
+    }
+
+    return total_dist;
+}