Zig day 3

README.md

@@ -13,9 +13,9 @@ Welcome to this community project, where we collaboratively solve the 2020 editi
 | deno.ts   |  **7** |  1   |  1  |  1  |  1   |  1  |  1  | 1   |    |    |    ||||||||||||||||
 | c         |  **6** |  1   |  1  |  1  |  1   |  1  |  1  |     |    |    |    ||||||||||||||||
 | node.js   |  **4** |  1   |     |     |  1   |     |  1  | 1   |    |    |    ||||||||||||||||
+| zig       |  **3** |  1   |  1  |  1  |      |     |     |     |    |    |    ||||||||||||||||
 | c++       |  **2** |  1   |  1  |     |      |     |     |     |    |    |    ||||||||||||||||
 | ruby      |  **2** |  1   |     |     |  1   |     |     |     |    |    |    ||||||||||||||||
-| zig       |  **2** |  1   |  1  |     |      |     |     |     |    |    |    ||||||||||||||||
 | rust      |  **1** |  1   |     |     |      |     |     |     |    |    |    ||||||||||||||||
 | bash      |  **0** |      |     |     |      |     |     |     |    |    |    ||||||||||||||||
 | java      |  **0** |      |     |     |      |     |     |     |    |    |    ||||||||||||||||

days/day-02/solutions/day02.zig

@@ -65,14 +65,14 @@ const RequirementPassword = struct {
         return occurence >= self.min;
     }
 
-     pub inline fn newValid(self: RequirementPassword) bool {
+    pub inline fn newValid(self: RequirementPassword) bool {
         var min_occurence: usize = @boolToInt(self.password[self.min - 1] == self.char);
         var max_occurence: usize = @boolToInt(self.password[self.max - 1] == self.char);
         return @as(usize, min_occurence) + @as(usize, max_occurence) == 1;
     }
 };
 
-fn bytesToRPPArrayList(allocator: *Allocator, bytes: []u8) !ArrayList(RequirementPassword) {
+fn bytesToParsedArrayList(allocator: *Allocator, bytes: []u8) !ArrayList(RequirementPassword) {
     var list = try ArrayList(RequirementPassword).initCapacity(allocator, 2000);
 
     var it = mem.split(bytes, "\n");
@@ -110,7 +110,7 @@ pub fn main() anyerror!void {
 
     const length = try in.readAll(&buf);
 
-    var parsed_input = try bytesToRPPArrayList(allocator, buf[0..length]);
+    var parsed_input = try bytesToParsedArrayList(allocator, buf[0..length]);
 
     var old_valid: u32 = 0;
     var new_valid: u32 = 0;

days/day-03/solutions/day03.zig

@@ -0,0 +1,66 @@
+const std = @import("std");
+const mem = std.mem;
+const io = std.io;
+const ArrayList = std.ArrayList;
+
+const MAX_FILE_SIZE = 20_000;
+
+const Map = struct {
+    bytes: []u8,
+    line_width: usize,
+    map_height: usize,
+
+    pub inline fn init(bytes: []u8) Map {
+        var line_width: usize = 0;
+        while (line_width < bytes.len) : (line_width += 1) {
+            switch(bytes[line_width]) {
+                '\n', '\r' => break,
+                else => continue
+            }
+        }
+
+        line_width += 1;
+
+        return Map {
+            .bytes = bytes,
+            .line_width = line_width,  // TODO: account for arbitrary line ending format
+            .map_height = @divFloor(bytes.len, line_width)
+        };
+    } 
+
+    pub inline fn inspectPath(self: Map, rigth: usize, down: usize) usize {
+        var x_pos: usize = 0;
+        var y_pos: usize = 0;
+        var closed: u32 = 0;
+
+        while (y_pos < self.map_height) {
+            var n_skipped = @divFloor(x_pos, self.line_width - 1);
+            var real_x = (x_pos + n_skipped) % self.line_width;
+            var real_y = y_pos * self.line_width;
+
+            closed += @boolToInt(self.bytes[real_x + real_y] == '#');
+
+            x_pos += rigth;
+            y_pos += down;
+        }
+
+        return closed;
+    }
+};
+
+
+
+pub fn main() anyerror!void {
+    const in = std.io.getStdIn().reader();
+    const stdout = std.io.getStdOut().writer();
+
+    var buf: [MAX_FILE_SIZE]u8 = undefined;
+    const length = try in.readAll(&buf);
+
+    var map = Map.init(buf[0..length]);
+
+    var path_3_1 = map.inspectPath(3, 1);
+    try stdout.print("{}\n", .{path_3_1});
+
+    try stdout.print("{}\n", .{map.inspectPath(1, 1) * path_3_1 * map.inspectPath(5, 1) * map.inspectPath(7, 1) * map.inspectPath(1, 2)});
+}

days/day-03/test.sh

@@ -6,6 +6,7 @@ D=$(dirname $(realpath $0))
 echo ""
 echo "--- Day 3: Counting trees ---"
 $D/../../languages/c.sh      $D/input.txt $D/output.txt $D/solutions/day03.c
+$D/../../languages/zig.sh    $D/input.txt $D/output.txt $D/solutions/day03.zig
 $D/../../languages/go.sh     $D/input.txt $D/output.txt $D/solutions/day03.stektpotet.go
 $D/../../languages/go.sh     $D/input.txt $D/output.txt $D/solutions/day03.tholok97.go
 $D/../../languages/sml.sh    $D/input.txt $D/output.txt $D/solutions/day03.sml