Implemented the y command requirements

src/field.zig

@@ -244,6 +244,9 @@ pub const Field = struct {
         if (y >= f.y and y < f.y + @intCast(i64, f.lines.items.len)) return f.lines.items[@intCast(usize, y - @intCast(i64, f.y))].get(x);
         return ' ';
     }
+    pub fn getSize(f: Field) [4]i64 {
+        return [4]i64{ f.x, f.y, @intCast(i64, f.lx), @intCast(i64, f.lines.items.len) };
+    }
     fn init(allocator: std.mem.Allocator) !*Field {
         var f = try allocator.create(Field);
         errdefer allocator.destroy(f);

src/stack.zig

@@ -147,6 +147,16 @@ pub const Stack = struct {
         const emptyResult2 = [_]i64{ 4, 5 };
         try std.testing.expectEqualSlices(i64, empty.data.items, emptyResult2[0..]);
     }
+    pub fn yCommandPick(self: *Stack, n: usize, h: usize) !void {
+        if (n > self.data.items.len) {
+            self.data.items.len = 1;
+            self.data.items[0] = 0;
+        } else {
+            const v = self.data.items[self.data.items.len - n];
+            self.data.items.len = h;
+            try self.push(v);
+        }
+    }
 };
 
 test "all" {