1 files changed, 16 insertions, 16 deletions
diff --git a/src/day10.zig b/src/day10.zig
index 13bed52..a0eb88d 100644
--- a/src/day10.zig
+++ b/src/day10.zig
@@ -125,16 +125,19 @@ fn part2(buffer: []const u8, allocator: std.mem.Allocator) !void {
         @memset(grid[i], 0);
     }
 
+    var list = std.ArrayList(std.meta.Tuple(&.{ usize, usize })).init(allocator);
+    defer list.deinit();
+
     var row: usize = 0;
     while (lines.next()) |line| {
         if (line.len == 0) break;
         for (line, 0..) |item, col| {
-            if (item == '.') {
-                grid[row][col] = 15;
-            } else {
-                grid[row][col] = item - '0';
+            grid[row][col] = item - '0';
+            if (item == '0') {
+                try list.append(.{ row, col });
             }
         }
+
         row += 1;
     }
 
@@ -143,19 +146,16 @@ fn part2(buffer: []const u8, allocator: std.mem.Allocator) !void {
     for (0..width) |i| {
         lookup[i] = try allocator.alloc(i32, width);
     }
+
     defer allocator.free(lookup);
-    for (0..width) |r| {
-        for (0..width) |c| {
-            if (grid[r][c] == 0) {
-                out += try dfs2(
-                    lookup,
-                    grid,
-                    @intCast(r),
-                    @intCast(c),
-                    -1,
-                );
-            }
-        }
+    for (list.items) |zero| {
+        out += try dfs2(
+            lookup,
+            grid,
+            @intCast(zero[0]),
+            @intCast(zero[1]),
+            -1,
+        );
     }
 
     for (0..width) |i| {