2023-21 part2 was... not fun, needed help from the megathread for sure

2023/day21/main_test.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"testing"
+)
+
+var example = `...........
+.....###.#.
+.###.##..#.
+..#.#...#..
+....#.#....
+.##..S####.
+.##..#...#.
+.......##..
+.##.#.####.
+.##..##.##.
+...........`
+
+func Test_part1(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		steps int
+		want  int
+	}{
+		{
+			name:  "example",
+			input: example,
+			steps: 6,
+			want:  16,
+		},
+		{
+			name:  "actual",
+			input: input,
+			steps: 64,
+			want:  3743,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := part1(tt.input, tt.steps); got != tt.want {
+				t.Errorf("part1() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_part2(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		steps int
+		want  int
+	}{
+		// {
+		// 	name:  "example-10",
+		// 	input: example,
+		// 	steps: 10,
+		// 	want:  50,
+		// },
+		// {
+		// 	name:  "example-50",
+		// 	input: example,
+		// 	steps: 50,
+		// 	want:  1594,
+		// },
+		// {
+		// 	name:  "example-100",
+		// 	input: example,
+		// 	steps: 100,
+		// 	want:  6536,
+		// },
+		// {
+		// 	name:  "example-5k",
+		// 	input: example,
+		// 	steps: 5000,
+		// 	want:  16733044,
+		// },
+		{
+			name:  "actual",
+			input: input,
+			steps: 26501365,
+			want:  618261433219147,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := part2(tt.input, tt.steps); got != tt.want {
+				t.Errorf("part2() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}