The polymer density profiles and the polymer-mediated interaction between parallel walls covered by irreversibly adsorbed polymer layers in good solvents are controlled by the crossover distance between the loops- and tails-regions, and the length of the tails. The relative value of these length scales strongly depends on the adsorbed polymer amount. For extremely over- and undersaturated surfaces (when the scales are well-separated), asymptotic expressions of the force and density profile have been previously obtained, at the mean-field level. We present here numerical results for the more general case of intermediate saturation. The predicted double layer structure of the adsorbed polymers is observed only when the walls are oversaturated. Saturated and oversaturated walls repel each other, while highly undersaturated walls interact only attractively. The interaction between slightly starved walls changes from repulsive to attractive as they come together, the amplitude of the repulsive barrier increasing with the surface coverage.