11-1

milanaleksic · Dec 11, 2023 · fa800af · fa800af
1 parent 35c29dc
commit fa800af
Showing 1 changed file with 47 additions and 12 deletions.
diff --git a/src/day11.zig b/src/day11.zig
@@ -2,6 +2,7 @@ const std = @import("std");
 const util = @import("util.zig");
 const mem = std.mem;
 const print = std.debug.print;
+const math = std.math;
 
 const NodeType = enum {
     Space,
@@ -16,14 +17,21 @@ const NodeType = enum {
     }
 };
 
+const Location = struct {
+    x: usize,
+    y: usize,
+};
+
 const Data = struct {
     const Self = @This();
     allocator: std.mem.Allocator,
 
+    galaxies: std.ArrayList(Location),
     rows: std.ArrayList(std.ArrayList(NodeType)),
 
     pub fn init(allocator: std.mem.Allocator, list: std.ArrayList([]const u8)) !Self {
         var rows: std.ArrayList(std.ArrayList(NodeType)) = try std.ArrayList(std.ArrayList(NodeType)).initCapacity(allocator, list.items.len);
+        var countOfGalaxies: usize = 0;
         for (list.items) |line| {
             // print("line={s}\n", .{line});
             var row: std.ArrayList(NodeType) = try std.ArrayList(NodeType).initCapacity(allocator, line.len);
@@ -32,6 +40,7 @@ const Data = struct {
                 const nodeType = NodeType.fromChar(char);
                 if (nodeType == NodeType.Galaxy) {
                     numberOfGalaxiesInRow += 1;
+                    countOfGalaxies += 1;
                 }
                 try row.append(nodeType);
             }
@@ -61,9 +70,22 @@ const Data = struct {
             }
             x += 1;
         }
+
+        var galaxies: std.ArrayList(Location) = try std.ArrayList(Location).initCapacity(allocator, countOfGalaxies);
+        for (rows.items, 0..) |rowData, yi| {
+            for (rowData.items, 0..) |cell, xi| {
+                if (cell == NodeType.Galaxy) {
+                    try galaxies.append(Location{
+                        .x = xi,
+                        .y = yi,
+                    });
+                }
+            }
+        }
         return Self{
             .rows = rows,
             .allocator = allocator,
+            .galaxies = galaxies,
         };
     }
 
@@ -72,6 +94,7 @@ const Data = struct {
             row.deinit();
         }
         self.rows.deinit();
+        self.galaxies.deinit();
     }
 
     pub fn printMap(self: *Self) void {
@@ -88,20 +111,32 @@ const Data = struct {
     }
 };
 
-pub fn part1(allocator: std.mem.Allocator, list: std.ArrayList([]const u8)) !i64 {
-    var sum: i64 = 0;
+fn manhattan(loc1: Location, loc2: Location) usize {
+    var loc1x: i64 = @bitCast(loc1.x);
+    var loc1y: i64 = @bitCast(loc1.y);
+    var loc2x: i64 = @bitCast(loc2.x);
+    var loc2y: i64 = @bitCast(loc2.y);
+    return math.absCast(loc1x - loc2x) + math.absCast(loc1y - loc2y);
+}
+
+pub fn part1(allocator: std.mem.Allocator, list: std.ArrayList([]const u8)) !usize {
+    var sum: usize = 0;
 
     var data = try Data.init(allocator, list);
     defer data.deinit();
 
-    data.printMap();
+    // data.printMap();
 
-    // access input data...
-    // for (data.rows.items) |rowData| {
-
-    // }
+    for (data.galaxies.items) |galaxy1| {
+        for (data.galaxies.items) |galaxy2| {
+            if (galaxy1.x == galaxy2.x and galaxy1.y == galaxy2.y) {
+                continue;
+            }
+            sum += manhattan(galaxy1, galaxy2);
+        }
+    }
 
-    return sum;
+    return @divTrunc(sum, 2);
 }
 
 test "part 1 test 1" {
@@ -119,16 +154,16 @@ test "part 1 test 1" {
     );
     defer list.deinit();
 
-    const testValue: i64 = try part1(std.testing.allocator, list);
-    try std.testing.expectEqual(testValue, -1);
+    const testValue: usize = try part1(std.testing.allocator, list);
+    try std.testing.expectEqual(testValue, 374);
 }
 
 test "part 1 full" {
     var data = try util.openFile(std.testing.allocator, "data/input-11-1.txt");
     defer data.deinit();
 
-    const testValue: i64 = try part1(std.testing.allocator, data.lines);
-    try std.testing.expectEqual(testValue, -1);
+    const testValue: usize = try part1(std.testing.allocator, data.lines);
+    try std.testing.expectEqual(testValue, 0);
 }
 
 pub fn part2(allocator: std.mem.Allocator, list: std.ArrayList([]const u8)) !i64 {