1 files changed, 48 insertions, 0 deletions
diff --git a/day-4/main.zig b/day-4/main.zig
new file mode 100644
index 0000000..e971b65
--- /dev/null
+++ b/day-4/main.zig
@@ -0,0 +1,48 @@
+const std = @import("std");
+const dupl_values = @import("util/mem.zig").dupl_values;
+
+pub fn puzzle_1(input: []u8) !u16 {
+    var iter = std.mem.split(u8, input, "\n");
+
+    var count: u16 = 0;
+    while (iter.next()) |line| {
+        const range = try parse_range(line);
+
+        if ((range[0][0] >= range[1][0] and range[0][1] <= range[1][1]) or
+            (range[0][0] <= range[1][0] and range[0][1] >= range[1][1]))
+            count += 1;
+    }
+
+    return count;
+}
+
+pub fn puzzle_2(input: []u8) !u16 {
+    var iter = std.mem.split(u8, input, "\n");
+
+    var count: u16 = 0;
+    while (iter.next()) |line| {
+        const range = try parse_range(line);
+
+        if ((range[0][0] >= range[1][0] and range[0][0] <= range[1][1]) or
+            (range[0][0] <= range[1][0] and range[0][1] >= range[1][0]))
+            count += 1;
+    }
+
+    return count;
+}
+
+fn parse_range(line: []const u8) ![2][2]u8 {
+    var r = std.mem.zeroes([2][2]u8);
+
+    var parts = std.mem.split(u8, line, ",");
+    var p1 = std.mem.split(u8, parts.next().?, "-");
+    var p2 = std.mem.split(u8, parts.next().?, "-");
+
+    r[0][0] = try std.fmt.parseInt(u8, p1.next().?, 0);
+    r[0][1] = try std.fmt.parseInt(u8, p1.next().?, 0);
+
+    r[1][0] = try std.fmt.parseInt(u8, p2.next().?, 0);
+    r[1][1] = try std.fmt.parseInt(u8, p2.next().?, 0);
+
+    return r;
+}