Day 11 binary attempt

2023-12-11 23:03:26 +00:00
parent 142ad95529
commit a8251b3f51
2 changed files with 154 additions and 3 deletions
--- a/AdventOfCode2023/src/day11/day11.zig
+++ b/AdventOfCode2023/src/day11/day11.zig
@@ -0,0 +1,150 @@
+const std = @import("std");
+const print = std.debug.print;
+
+const GALAXY = 1;
+const SPACE = 0;
+
+fn min(num1: u256, num2: u256) usize {
+    if (num1 > num2) {
+        return @truncate(num2);
+    }
+    return @truncate(num1);
+}
+
+fn max(num1: u256, num2: u256) usize {
+    if (num1 <= num2) {
+        return @truncate(num2);
+    }
+    return @truncate(num1);
+}
+
+pub fn solve(input: [][]const u8) !void {
+    var allocator = std.heap.page_allocator;
+
+    var grid = try allocator.alloc(u256, input.len);
+    var index: usize = 0;
+
+    for (input) |line| {
+        var line1: u256 = 0;
+        for (line) |_c| {
+            var c: u8 = 0;
+            if (_c == '.') {
+                c = SPACE;
+            } else {
+                c = GALAXY;
+            }
+
+            line1 = (line1 << 1) | @as(u256, c);
+        }
+
+        grid[index] = line1;
+        index += 1;
+    }
+
+    var rows: u256 = 0;
+    var cols: u256 = 0;
+
+    for (grid) |row| {
+        if (row == 0) {
+            rows = (rows << 1) | @as(u256, 1);
+            continue;
+        }
+        rows = rows << 1;
+    }
+
+    for (0..input[0].len) |i| {
+        var empty = true;
+        for (grid) |row| {
+            var truncated: u8 = @truncate(input[0].len - i - 1);
+            if (row & @as(u256, @as(u256, 1) << truncated) != 0) {
+                empty = false;
+                break;
+            }
+        }
+
+        if (empty) {
+            cols = (cols << 1) | @as(u256, 1);
+            continue;
+        }
+        cols = cols << 1;
+    }
+
+    var pair: usize = 0;
+    var part1: usize = 0;
+
+    for (grid, 0..) |row, i| {
+        var galaxy: u265 = 1;
+        for (1..256) |k1| {
+            var comp1 = galaxy & row;
+            if (comp1 > 0) {
+
+                //
+                // We found galaxy!
+                //
+
+                for (i..grid.len) |j| {
+                    var rowAgain = grid[j];
+                    var galaxy2: u265 = 1;
+
+                    for (1..256) |k2| {
+                        var comp2 = galaxy2 & rowAgain;
+                        if (comp2 > 0) {
+                            var found = i != j or k2 > k1;
+
+                            if (found) {
+                                pair += 1;
+                                var distY: u256 = 0;
+                                if (k1 > k2) {
+                                    distY = k1 - k2;
+                                } else {
+                                    distY = k2 - k1;
+                                }
+
+                                // print("Galaxy 1 | {},{}\n", .{ k1, i });
+                                // print("Galaxy 2 | {},{}\n", .{ k2, j });
+
+                                var emptyRows: u256 = 0;
+                                var emptyCols: u256 = 0;
+
+                                if (i != j) {
+                                    for (i + 1..j) |_shift| {
+                                        var shift: u8 = @truncate(_shift);
+                                        var u8Length: u8 = @truncate(input.len);
+                                        var r = @as(u256, 1) << (u8Length - shift - 1);
+
+                                        if (r & rows > 0) {
+                                            emptyRows += 1;
+                                        }
+                                    }
+                                }
+
+                                if (k1 != k2) {
+                                    for (min(k1, k2) + 1..max(k1, k2)) |_shift| {
+                                        var shift: u8 = @truncate(_shift);
+                                        var u8Length: u8 = @truncate(input[0].len);
+                                        var r = @as(u256, 1) << (u8Length - shift - 1);
+
+                                        if (r & cols > 0) {
+                                            emptyCols += 1;
+                                        }
+                                    }
+                                }
+
+                                var dist = distY + (j - i) + emptyRows + emptyCols;
+
+                                print("Distance: {}\n", .{dist});
+                                print("---\n", .{});
+                                part1 += @truncate(dist);
+                            }
+                        }
+                        galaxy2 = galaxy2 << 1;
+                    }
+                }
+            }
+            galaxy = galaxy << 1;
+        }
+    }
+
+    print("Pairs: {}\n", .{pair});
+    print("Part 1: {}\n", .{part1});
+}