day 5 in zig

zig/5/input.txt

@@ -0,0 +1,512 @@
+[T]     [D]         [L]            
+[R]     [S] [G]     [P]         [H]
+[G]     [H] [W]     [R] [L]     [P]
+[W]     [G] [F] [H] [S] [M]     [L]
+[Q]     [V] [B] [J] [H] [N] [R] [N]
+[M] [R] [R] [P] [M] [T] [H] [Q] [C]
+[F] [F] [Z] [H] [S] [Z] [T] [D] [S]
+[P] [H] [P] [Q] [P] [M] [P] [F] [D]
+ 1   2   3   4   5   6   7   8   9 
+
+move 3 from 8 to 9
+move 2 from 2 to 8
+move 5 from 4 to 2
+move 7 from 1 to 4
+move 3 from 8 to 2
+move 3 from 2 to 7
+move 1 from 7 to 4
+move 3 from 2 to 9
+move 4 from 7 to 9
+move 1 from 5 to 2
+move 2 from 3 to 4
+move 5 from 9 to 5
+move 6 from 9 to 3
+move 5 from 9 to 5
+move 1 from 9 to 7
+move 2 from 3 to 1
+move 7 from 3 to 9
+move 2 from 7 to 2
+move 5 from 2 to 4
+move 1 from 2 to 9
+move 2 from 1 to 9
+move 7 from 6 to 1
+move 2 from 7 to 3
+move 2 from 3 to 9
+move 1 from 7 to 4
+move 1 from 9 to 2
+move 3 from 1 to 8
+move 2 from 3 to 4
+move 5 from 9 to 2
+move 1 from 3 to 9
+move 8 from 5 to 7
+move 1 from 6 to 1
+move 15 from 4 to 1
+move 4 from 2 to 5
+move 5 from 9 to 7
+move 1 from 9 to 5
+move 5 from 1 to 2
+move 3 from 8 to 9
+move 1 from 7 to 6
+move 11 from 1 to 2
+move 7 from 5 to 3
+move 4 from 2 to 6
+move 7 from 3 to 4
+move 3 from 5 to 9
+move 2 from 2 to 5
+move 5 from 1 to 8
+move 2 from 6 to 8
+move 3 from 8 to 9
+move 9 from 4 to 9
+move 9 from 7 to 4
+move 2 from 8 to 1
+move 1 from 8 to 7
+move 6 from 2 to 7
+move 5 from 2 to 4
+move 5 from 7 to 2
+move 2 from 1 to 7
+move 2 from 6 to 4
+move 7 from 7 to 1
+move 3 from 2 to 6
+move 1 from 8 to 7
+move 2 from 9 to 3
+move 2 from 3 to 1
+move 1 from 2 to 5
+move 4 from 6 to 5
+move 2 from 2 to 3
+move 3 from 5 to 7
+move 1 from 5 to 3
+move 9 from 1 to 7
+move 2 from 9 to 5
+move 13 from 4 to 1
+move 5 from 7 to 2
+move 3 from 3 to 1
+move 2 from 2 to 9
+move 1 from 2 to 7
+move 5 from 5 to 6
+move 2 from 2 to 4
+move 5 from 1 to 3
+move 9 from 7 to 8
+move 2 from 9 to 5
+move 3 from 5 to 4
+move 5 from 9 to 2
+move 10 from 4 to 8
+move 1 from 4 to 1
+move 2 from 8 to 4
+move 4 from 8 to 2
+move 3 from 6 to 8
+move 7 from 8 to 7
+move 10 from 9 to 3
+move 7 from 3 to 2
+move 11 from 2 to 3
+move 13 from 3 to 9
+move 1 from 6 to 3
+move 1 from 1 to 2
+move 1 from 2 to 8
+move 3 from 3 to 4
+move 1 from 2 to 9
+move 1 from 4 to 1
+move 10 from 8 to 3
+move 11 from 9 to 7
+move 1 from 6 to 2
+move 14 from 7 to 1
+move 2 from 2 to 9
+move 4 from 7 to 6
+move 1 from 2 to 4
+move 3 from 4 to 2
+move 4 from 2 to 9
+move 10 from 3 to 4
+move 3 from 6 to 1
+move 5 from 9 to 5
+move 5 from 5 to 8
+move 1 from 9 to 7
+move 2 from 9 to 6
+move 1 from 9 to 8
+move 2 from 4 to 8
+move 1 from 4 to 5
+move 2 from 3 to 1
+move 2 from 3 to 7
+move 27 from 1 to 2
+move 2 from 7 to 1
+move 9 from 4 to 6
+move 9 from 6 to 5
+move 5 from 8 to 6
+move 26 from 2 to 3
+move 1 from 2 to 5
+move 1 from 2 to 7
+move 1 from 8 to 4
+move 1 from 7 to 8
+move 24 from 3 to 5
+move 1 from 8 to 5
+move 1 from 4 to 3
+move 1 from 7 to 1
+move 1 from 8 to 9
+move 7 from 1 to 7
+move 8 from 6 to 4
+move 4 from 7 to 6
+move 1 from 3 to 9
+move 2 from 9 to 1
+move 3 from 7 to 9
+move 8 from 4 to 6
+move 3 from 9 to 1
+move 1 from 3 to 6
+move 1 from 8 to 2
+move 10 from 5 to 4
+move 1 from 3 to 8
+move 13 from 5 to 3
+move 1 from 2 to 9
+move 1 from 8 to 9
+move 1 from 3 to 8
+move 1 from 9 to 2
+move 3 from 6 to 9
+move 7 from 4 to 9
+move 4 from 3 to 9
+move 2 from 6 to 8
+move 2 from 4 to 5
+move 10 from 9 to 3
+move 1 from 1 to 9
+move 1 from 4 to 8
+move 1 from 1 to 4
+move 1 from 4 to 5
+move 4 from 6 to 3
+move 1 from 9 to 5
+move 1 from 6 to 9
+move 2 from 6 to 5
+move 1 from 9 to 2
+move 1 from 6 to 7
+move 18 from 5 to 2
+move 22 from 3 to 7
+move 19 from 7 to 1
+move 3 from 8 to 5
+move 4 from 9 to 3
+move 2 from 7 to 2
+move 1 from 8 to 1
+move 19 from 1 to 3
+move 2 from 7 to 5
+move 13 from 3 to 9
+move 4 from 1 to 2
+move 3 from 5 to 1
+move 11 from 9 to 1
+move 11 from 2 to 8
+move 3 from 9 to 3
+move 3 from 5 to 2
+move 2 from 1 to 4
+move 5 from 2 to 7
+move 12 from 1 to 5
+move 2 from 4 to 5
+move 9 from 5 to 8
+move 1 from 5 to 3
+move 4 from 2 to 3
+move 2 from 7 to 5
+move 6 from 2 to 8
+move 17 from 8 to 9
+move 2 from 9 to 6
+move 2 from 7 to 1
+move 15 from 9 to 6
+move 2 from 2 to 4
+move 9 from 8 to 5
+move 2 from 1 to 3
+move 12 from 6 to 2
+move 2 from 3 to 9
+move 5 from 6 to 3
+move 4 from 5 to 3
+move 11 from 3 to 4
+move 2 from 9 to 4
+move 6 from 5 to 2
+move 13 from 4 to 3
+move 1 from 4 to 5
+move 1 from 4 to 8
+move 18 from 2 to 6
+move 2 from 5 to 3
+move 1 from 8 to 3
+move 1 from 2 to 5
+move 1 from 7 to 8
+move 28 from 3 to 6
+move 2 from 3 to 4
+move 3 from 5 to 9
+move 2 from 5 to 9
+move 3 from 9 to 3
+move 5 from 3 to 4
+move 1 from 9 to 3
+move 1 from 9 to 1
+move 1 from 3 to 4
+move 45 from 6 to 2
+move 1 from 8 to 3
+move 2 from 4 to 6
+move 5 from 4 to 2
+move 1 from 3 to 7
+move 3 from 2 to 9
+move 1 from 4 to 8
+move 3 from 6 to 1
+move 42 from 2 to 8
+move 2 from 9 to 2
+move 4 from 2 to 6
+move 2 from 2 to 7
+move 1 from 9 to 6
+move 2 from 8 to 9
+move 4 from 1 to 8
+move 1 from 6 to 4
+move 1 from 4 to 8
+move 1 from 2 to 5
+move 3 from 7 to 4
+move 39 from 8 to 3
+move 7 from 8 to 5
+move 8 from 5 to 7
+move 35 from 3 to 1
+move 4 from 3 to 7
+move 10 from 7 to 2
+move 2 from 9 to 6
+move 3 from 4 to 2
+move 1 from 7 to 5
+move 1 from 7 to 8
+move 1 from 5 to 4
+move 12 from 1 to 6
+move 1 from 8 to 1
+move 1 from 4 to 5
+move 14 from 6 to 8
+move 9 from 8 to 6
+move 5 from 6 to 1
+move 11 from 2 to 9
+move 1 from 9 to 8
+move 6 from 8 to 3
+move 6 from 9 to 2
+move 8 from 1 to 9
+move 3 from 3 to 6
+move 7 from 1 to 4
+move 1 from 5 to 9
+move 8 from 9 to 8
+move 7 from 6 to 8
+move 1 from 9 to 3
+move 3 from 6 to 4
+move 3 from 9 to 1
+move 4 from 3 to 2
+move 1 from 6 to 7
+move 1 from 4 to 2
+move 13 from 1 to 7
+move 6 from 4 to 8
+move 1 from 7 to 3
+move 1 from 4 to 6
+move 1 from 9 to 5
+move 1 from 3 to 5
+move 19 from 8 to 9
+move 1 from 6 to 5
+move 6 from 9 to 2
+move 2 from 5 to 8
+move 1 from 5 to 2
+move 4 from 1 to 4
+move 8 from 9 to 4
+move 3 from 9 to 8
+move 2 from 9 to 1
+move 6 from 7 to 5
+move 12 from 4 to 2
+move 6 from 8 to 3
+move 1 from 4 to 1
+move 1 from 3 to 1
+move 13 from 2 to 3
+move 4 from 5 to 3
+move 1 from 4 to 9
+move 1 from 8 to 9
+move 12 from 3 to 2
+move 1 from 9 to 1
+move 2 from 5 to 9
+move 3 from 9 to 5
+move 1 from 7 to 5
+move 3 from 7 to 3
+move 1 from 5 to 4
+move 1 from 5 to 8
+move 9 from 2 to 3
+move 2 from 2 to 3
+move 3 from 1 to 9
+move 1 from 8 to 9
+move 3 from 9 to 1
+move 9 from 2 to 6
+move 1 from 9 to 5
+move 6 from 2 to 3
+move 2 from 6 to 9
+move 3 from 6 to 3
+move 1 from 4 to 3
+move 2 from 9 to 6
+move 2 from 7 to 2
+move 2 from 2 to 8
+move 24 from 3 to 7
+move 2 from 5 to 6
+move 2 from 8 to 2
+move 7 from 2 to 8
+move 8 from 3 to 6
+move 2 from 1 to 3
+move 1 from 1 to 2
+move 1 from 5 to 2
+move 15 from 7 to 4
+move 9 from 7 to 9
+move 7 from 9 to 1
+move 5 from 8 to 1
+move 4 from 1 to 4
+move 19 from 4 to 3
+move 22 from 3 to 5
+move 1 from 7 to 5
+move 9 from 5 to 4
+move 6 from 1 to 3
+move 6 from 3 to 1
+move 4 from 5 to 4
+move 1 from 2 to 1
+move 1 from 2 to 6
+move 4 from 6 to 1
+move 1 from 3 to 6
+move 3 from 6 to 3
+move 2 from 9 to 8
+move 2 from 5 to 3
+move 2 from 5 to 1
+move 10 from 6 to 4
+move 4 from 4 to 9
+move 7 from 4 to 3
+move 2 from 8 to 7
+move 4 from 9 to 3
+move 5 from 5 to 7
+move 1 from 5 to 1
+move 1 from 6 to 3
+move 1 from 8 to 4
+move 1 from 8 to 3
+move 13 from 4 to 5
+move 1 from 1 to 8
+move 6 from 5 to 3
+move 1 from 7 to 6
+move 5 from 7 to 6
+move 9 from 1 to 8
+move 1 from 8 to 4
+move 1 from 7 to 1
+move 1 from 4 to 1
+move 5 from 3 to 7
+move 3 from 7 to 9
+move 1 from 5 to 4
+move 6 from 8 to 6
+move 1 from 9 to 3
+move 2 from 9 to 5
+move 7 from 5 to 9
+move 1 from 7 to 5
+move 2 from 5 to 3
+move 10 from 6 to 8
+move 2 from 6 to 1
+move 1 from 4 to 9
+move 1 from 7 to 5
+move 8 from 8 to 2
+move 1 from 1 to 7
+move 1 from 9 to 7
+move 1 from 5 to 1
+move 3 from 9 to 8
+move 7 from 8 to 7
+move 6 from 7 to 1
+move 1 from 8 to 7
+move 4 from 7 to 1
+move 16 from 3 to 7
+move 4 from 3 to 1
+move 5 from 7 to 8
+move 16 from 1 to 4
+move 9 from 1 to 7
+move 1 from 3 to 4
+move 15 from 4 to 8
+move 1 from 3 to 1
+move 2 from 1 to 6
+move 2 from 4 to 9
+move 17 from 8 to 2
+move 6 from 9 to 5
+move 8 from 7 to 8
+move 2 from 6 to 9
+move 4 from 5 to 7
+move 2 from 8 to 5
+move 1 from 5 to 9
+move 11 from 2 to 6
+move 4 from 6 to 1
+move 5 from 2 to 8
+move 2 from 9 to 2
+move 1 from 9 to 3
+move 3 from 1 to 8
+move 1 from 3 to 6
+move 7 from 6 to 9
+move 2 from 5 to 4
+move 6 from 7 to 4
+move 4 from 8 to 1
+move 1 from 5 to 2
+move 1 from 6 to 1
+move 7 from 9 to 8
+move 2 from 7 to 9
+move 9 from 2 to 9
+move 5 from 9 to 3
+move 3 from 2 to 8
+move 4 from 8 to 7
+move 9 from 7 to 2
+move 3 from 1 to 3
+move 14 from 8 to 1
+move 2 from 8 to 3
+move 1 from 9 to 4
+move 3 from 7 to 9
+move 8 from 3 to 9
+move 2 from 2 to 7
+move 12 from 1 to 8
+move 4 from 1 to 6
+move 2 from 6 to 7
+move 1 from 6 to 7
+move 9 from 4 to 7
+move 9 from 7 to 4
+move 1 from 1 to 6
+move 2 from 3 to 6
+move 2 from 6 to 8
+move 12 from 9 to 8
+move 2 from 6 to 9
+move 2 from 9 to 7
+move 1 from 8 to 5
+move 5 from 7 to 5
+move 1 from 9 to 1
+move 3 from 4 to 1
+move 5 from 4 to 8
+move 4 from 1 to 7
+move 1 from 4 to 2
+move 19 from 8 to 4
+move 2 from 7 to 5
+move 14 from 8 to 5
+move 2 from 7 to 8
+move 3 from 9 to 8
+move 19 from 4 to 2
+move 9 from 2 to 4
+move 2 from 7 to 8
+move 15 from 5 to 9
+move 15 from 9 to 8
+move 1 from 5 to 9
+move 11 from 8 to 7
+move 4 from 5 to 8
+move 1 from 5 to 9
+move 2 from 9 to 5
+move 2 from 2 to 6
+move 14 from 2 to 9
+move 12 from 8 to 9
+move 3 from 8 to 4
+move 7 from 9 to 2
+move 4 from 7 to 9
+move 1 from 6 to 9
+move 1 from 7 to 5
+move 1 from 6 to 2
+move 3 from 5 to 4
+move 19 from 9 to 4
+move 1 from 5 to 1
+move 1 from 9 to 8
+move 1 from 1 to 7
+move 1 from 8 to 9
+move 4 from 7 to 2
+move 3 from 7 to 6
+move 18 from 4 to 2
+move 17 from 2 to 3
+move 2 from 6 to 8
+move 17 from 3 to 6
+move 13 from 2 to 1
+move 2 from 8 to 3
+move 2 from 2 to 9
+move 6 from 1 to 9
+move 1 from 3 to 4
+move 1 from 3 to 9
+move 8 from 6 to 4
+move 20 from 4 to 8
+move 3 from 4 to 8
+move 15 from 8 to 2
+move 11 from 2 to 6
+move 2 from 1 to 7
+move 7 from 9 to 8
+move 6 from 9 to 3
+move 1 from 6 to 5

zig/5/part1.zig

@@ -0,0 +1,75 @@
+const std = @import("std");
+
+const State = enum { Parse, Move };
+
+pub fn main() !void {
+    var file = try std.fs.cwd().openFile("input.txt", .{});
+    defer file.close();
+
+    var a = std.io.bufferedReader(file.reader());
+    var readerStream = a.reader();
+
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    const allocator = gpa.allocator();
+
+    const stackCharWidth = 4;
+    var stackCount: ?u32 = null;
+    var state = State.Parse;
+    var stacks = std.ArrayList(std.ArrayList(u8)).init(allocator);
+    defer {
+        for (stacks.items) |stack| {
+            stack.deinit();
+        }
+        stacks.deinit();
+    }
+
+    var buf: [200]u8 = undefined;
+    while (try readerStream.readUntilDelimiterOrEof(&buf, '\n')) |line| {
+        switch (state) {
+            State.Parse => {
+                if (stackCount == null) {
+                    // first iteration - allocate stacks
+                    stackCount = (@intCast(u32, line.len) + 1) / stackCharWidth;
+                    var i: u32 = 0;
+                    while (i < stackCount.?) : (i += 1) {
+                        try stacks.append(std.ArrayList(u8).init(allocator));
+                    }
+                }
+
+                if (std.mem.eql(u8, line, "")) {
+                    // done parsing
+                    state = State.Move;
+                    for (stacks.items) |*stack| {
+                        _ = stack.pop(); // the stack's index number that also gets parsed
+                        std.mem.reverse(u8, stack.items);
+                    }
+                } else {
+                    // parse stacks
+                    for (stacks.items) |*stack, i| {
+                        const charIdx = i * stackCharWidth + 1;
+                        const char = line[charIdx .. charIdx + 1];
+                        if (char[0] != ' ') try stack.append(char[0]);
+                    }
+                }
+            },
+            State.Move => {
+                var tokens = std.mem.split(u8, line, " ");
+                _ = tokens.next(); // skip "move"
+                const iterations = try std.fmt.parseInt(u32, tokens.next().?, 10);
+                _ = tokens.next(); // skip "from"
+                const src = try std.fmt.parseInt(u32, tokens.next().?, 10) - 1;
+                _ = tokens.next(); // skip "to"
+                const dest = try std.fmt.parseInt(u32, tokens.next().?, 10) - 1;
+                var i: u32 = 0;
+                while (i < iterations) : (i += 1) {
+                    const tmp = stacks.items[src].pop();
+                    try stacks.items[dest].append(tmp);
+                }
+            },
+        }
+    }
+    for (stacks.items) |*stack| {
+        std.debug.print("{c}", .{stack.pop()});
+    }
+    std.debug.print("\n", .{});
+}

zig/5/part2.zig

@@ -0,0 +1,77 @@
+const std = @import("std");
+
+const State = enum { Parse, Move };
+
+pub fn main() !void {
+    var file = try std.fs.cwd().openFile("input.txt", .{});
+    defer file.close();
+
+    var a = std.io.bufferedReader(file.reader());
+    var readerStream = a.reader();
+
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    const allocator = gpa.allocator();
+
+    const stackCharWidth = 4;
+    var stackCount: ?u32 = null;
+    var state = State.Parse;
+    var stacks = std.ArrayList(std.ArrayList(u8)).init(allocator);
+    defer {
+        for (stacks.items) |stack| {
+            stack.deinit();
+        }
+        stacks.deinit();
+    }
+
+    var buf: [200]u8 = undefined;
+    while (try readerStream.readUntilDelimiterOrEof(&buf, '\n')) |line| {
+        switch (state) {
+            State.Parse => {
+                if (stackCount == null) {
+                    // first iteration - allocate stacks
+                    stackCount = (@intCast(u32, line.len) + 1) / stackCharWidth;
+                    var i: u32 = 0;
+                    while (i < stackCount.?) : (i += 1) {
+                        try stacks.append(std.ArrayList(u8).init(allocator));
+                    }
+                }
+
+                if (std.mem.eql(u8, line, "")) {
+                    // done parsing
+                    state = State.Move;
+                    for (stacks.items) |*stack| {
+                        _ = stack.pop(); // the stack's index number that also gets parsed
+                        std.mem.reverse(u8, stack.items);
+                    }
+                } else {
+                    // parse stacks
+                    for (stacks.items) |*stack, i| {
+                        const charIdx = i * stackCharWidth + 1;
+                        const char = line[charIdx .. charIdx + 1];
+                        if (char[0] != ' ') try stack.append(char[0]);
+                    }
+                }
+            },
+            State.Move => {
+                var tokens = std.mem.split(u8, line, " ");
+                _ = tokens.next(); // skip "move"
+                const iterations = try std.fmt.parseInt(u32, tokens.next().?, 10);
+                _ = tokens.next(); // skip "from"
+                const src = try std.fmt.parseInt(u32, tokens.next().?, 10) - 1;
+                _ = tokens.next(); // skip "to"
+                const dest = try std.fmt.parseInt(u32, tokens.next().?, 10) - 1;
+                var i: u32 = 0;
+                while (i < iterations) : (i += 1) {
+                    const tmp = stacks.items[src].pop();
+                    try stacks.items[dest].append(tmp);
+                }
+                const destItems = stacks.items[dest].items;
+                std.mem.reverse(u8, destItems[destItems.len - iterations ..]);
+            },
+        }
+    }
+    for (stacks.items) |*stack| {
+        std.debug.print("{c}", .{stack.pop()});
+    }
+    std.debug.print("\n", .{});
+}