  We have analysed the effect of intrinsic doping inhomogeneity and the
presence of stripes in high-T_c superconductors on coupling \lambda by using a
simple analytically solvable model with an angular dependent \lambda (\phi)
represented by a square-well form. We have found that the introduction of the
Coulomb repulsion \lambda_C, increasing the ''contrast'' | \lambda | + |
\lambda_C |, or the depth of the angular modulation of \lambda (\phi), leads to
a remarkable enhancement of T_c. This effect can be optimized by combining
attractive (\lambda <0) and repulsive (\lambda >0) interactions along stripes
and perpendicular to them.
