aoc2025/day12/shape.zig

const std = @import("std");

pub const kShapeSize: u8 = 3;

pub const Shape = struct {
    data: [9]u8,

    pub fn getCell(self: *const Shape, row: u8, col: u8) u8 {
        return self.data[row*kShapeSize + col];
    }

    pub fn setCell(self: *Shape, row: u8, col: u8, cell: u8) void {
        self.data[row*kShapeSize + col] = cell;
    }

    pub fn flipHor(self: *Shape) void {
        for (0 .. kShapeSize) |row| {
            for (0 .. kShapeSize/2) |col| {
                const t = self.getCell(@intCast(row), @intCast(col));
                self.setCell(@intCast(row), @intCast(col), 
                             self.getCell(@intCast(row),
                                          @intCast(kShapeSize - 1 - col)));
                self.setCell(@intCast(row), @intCast(kShapeSize - 1 - col), t);
            }
        }
    }

    pub fn flipVer(self: *Shape) void {
        for (0 .. kShapeSize) |col| {
            for (0 .. kShapeSize/2) |row| {
                const t = self.getCell(@intCast(row), @intCast(col));
                self.setCell(@intCast(row), @intCast(col), 
                             self.getCell(@intCast(kShapeSize - 1 - row),
                                          @intCast(col)));
                self.setCell(@intCast(kShapeSize - 1 - row), @intCast(col), t);
            }
        }
    }


    pub fn rotate(self: *Shape) void {
        for (0 .. kShapeSize-1) |row| {
            for (row+1 .. kShapeSize) |col| {
                const t = self.getCell(@intCast(row), @intCast(col));
                self.setCell(@intCast(row), @intCast(col),
                             self.getCell(@intCast(col), @intCast(row)));
                self.setCell(@intCast(col), @intCast(row), t);
            }
        }

        self.flipHor();
    }

    pub fn getAllTransforms(self: * const Shape, allocator: std.mem.Allocator) !std.AutoHashMap(Shape, bool) {
        var allTransforms = std.AutoHashMap(Shape, bool).init(allocator);

        try allTransforms.put(self.*, true);


        var shapeHFlip = self.*;
        shapeHFlip.flipHor();

        for (0 .. 4) |_| {
            try allTransforms.put(shapeHFlip, true);
            shapeHFlip.rotate();
        }

        var shapeVFlip = self.*;
        shapeVFlip.flipVer();

        for (0 .. 4) |_| {
            try allTransforms.put(shapeVFlip, true);
            shapeVFlip.rotate();
        }


        var shapeHVFlip = self.*;
        shapeHVFlip.flipHor();
        shapeHVFlip.flipVer();

        for (0 .. 4) |_| {
            try allTransforms.put(shapeHVFlip, true);
            shapeHVFlip.rotate();
        }

        var shapeVHFlip = self.*;
        shapeVHFlip.flipVer();
        shapeVHFlip.flipHor();

        for (0 .. 4) |_| {
            try allTransforms.put(shapeVHFlip, true);
            shapeVHFlip.rotate();
        }

        return allTransforms;
    }

    pub fn print(self: *const Shape, allocator: std.mem.Allocator) !void {
        for (0..kShapeSize) |row| {
            for (0..kShapeSize) |col| {
                const cell = self.getCell(@intCast(row), @intCast(col));
                try std.fs.File.stdout().writeAll(
                  try std.fmt.allocPrint(allocator, "{c}", .{cell}));
        
            }
            try std.fs.File.stdout().writeAll("\n");
        }
    }
};