PATHS AND CYCLES IN COLORED GRAPHS

Let G be an (edge-)colored graph. A path (cycle) is called monochromatic if all the edges of it have the same color, and is called heterochromatic if all the edges of it have different colors. In this note, some sufficient conditions for the existence of monochromatic and heterochromatic paths and cycles are obtained. We also propose a conjecture on the existence of paths and cycles with many colors.