day01: part1

.gitignore

@@ -69,3 +69,6 @@ docgen_tmp/
 
 ### nix ###
 result
+
+### local ###
+src/data

src/day01.zig

@@ -1,4 +1,48 @@
 const std = @import("std");
 const util = @import("util.zig");
 
-pub fn main() !void {}
+pub fn main() !void {
+    const input = @embedFile("data/day01.txt");
+    const sln = try solve(input);
+    std.debug.print("Part 1: {d}", .{sln});
+}
+
+fn solve(input: []const u8) !u32 {
+    var sum: u32 = 0;
+
+    var it = std.mem.splitAny(u8, input, "\n");
+    while (it.next()) |line| {
+        if (std.mem.eql(u8, "", line)) {
+            continue;
+        }
+
+        var first: u8 = 0;
+        var last: u8 = 0;
+        for (line) |char| {
+            if (char < '0' or char > '9') {
+                continue;
+            }
+            if (first == 0) {
+                first = char;
+            }
+            last = char;
+        }
+
+        const zero = @as(u8, '0');
+        const cal_value = (first - zero) * 10 + (last - zero);
+        sum += cal_value;
+    }
+
+    return sum;
+}
+
+test "sample" {
+    const input =
+        \\1abc2
+        \\pqr3stu8vwx
+        \\a1b2c3d4e5f
+        \\treb7uchet
+    ;
+    const sln = try solve(input);
+    try std.testing.expectEqual(@as(u32, 142), sln);
+}