The ornamental design for a laptopcomputer, as shown and described.
FIG. 1 is a perspective view of a laptop computer shown opened;
FIG. 2 is a top view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a back view thereof;
FIG. 5 is a right-side view thereof; and,
FIG. 6 is a left-side view thereof.
The broken lines shown in the drawings depicting a keyboard disposed on the lower portion of the laptop computer are included for additional clarity and form no part of the claimed design, and the broken lines shown in the drawings depicting the housing of the laptop computer are included for additional clarity and form no part of the claimed design.