add day 5

1 files changed, 61 insertions, 0 deletions

diff --git a/day_01.zig b/day_01.zig
new file mode 100644
index 0000000..80bb649
--- /dev/null
+++ b/day_01.zig
@@ -0,0 +1,61 @@
+const std = @import("std");
+const math = std.math;
+const Result = @import("util/aoc.zig").Result;
+
+pub fn puzzle_1(input: []const u8) !Result {
+    var iter = std.mem.split(u8, input, "\n");
+    var count: i32 = 0;
+    var max: i32 = 0;
+
+    while (iter.next()) |line| {
+        if (line.len == 0) {
+            if (count > max) {
+                max = count;
+            }
+            count = 0;
+        } else {
+            count += try std.fmt.parseInt(i32, line, 0);
+        }
+    }
+
+    return .{ .int = max };
+}
+
+pub fn puzzle_2(input: []const u8) !Result {
+    var iter = std.mem.split(u8, input, "\n");
+    var count: i32 = 0;
+    var max: [3]i32 = std.mem.zeroes([3]i32);
+
+    while (iter.next()) |line| {
+        if (line.len == 0) {
+            const lowest_u = min_idx(i32, &max);
+            if (count > max[lowest_u]) {
+                max[lowest_u] = count;
+            }
+            count = 0;
+        } else {
+            count += try std.fmt.parseInt(i32, line, 0);
+        }
+    }
+
+    count = 0;
+    for (max) |v| {
+        count += v;
+    }
+
+    return .{ .int = count };
+}
+
+fn min_idx(comptime T: type, slice: []const T) usize {
+    var best = slice[0];
+    var idx: usize = 0;
+
+    for (slice[1..]) |item, i| {
+        const possible_best = math.min(best, item);
+        if (best > possible_best) {
+            best = possible_best;
+            idx = i + 1;
+        }
+    }
+    return idx;
+}