In this paper, the authors discuss the upper bound for the genus of strong embeddings for 3-connected planar graphs on higher surfaces. It is shown that the problem of determining the upper bound for the strong embedd...In this paper, the authors discuss the upper bound for the genus of strong embeddings for 3-connected planar graphs on higher surfaces. It is shown that the problem of determining the upper bound for the strong embedding of 3-connected planar near-triangulations on higher non-orientable surfaces is NP-hard. As a corollary, a theorem of Richter, Seymour and Siran about the strong embedding of 3-connected planar graphs is generalized to orientable surface.展开更多
A near-triangulation is such a connected planar graph whose inner faces are all triangles but the outer face may be not. Let G be a near-triangulation of order n and C be an SCDC (small circuit double cover)[2] of G. ...A near-triangulation is such a connected planar graph whose inner faces are all triangles but the outer face may be not. Let G be a near-triangulation of order n and C be an SCDC (small circuit double cover)[2] of G. Let Then, C0 is said to he an equilibrium SCDC of G. In this paper, we show that if G is an outer planar graph, δ(C0)≤2, otherwiseδ(C0) ≤4.展开更多
文摘In this paper, the authors discuss the upper bound for the genus of strong embeddings for 3-connected planar graphs on higher surfaces. It is shown that the problem of determining the upper bound for the strong embedding of 3-connected planar near-triangulations on higher non-orientable surfaces is NP-hard. As a corollary, a theorem of Richter, Seymour and Siran about the strong embedding of 3-connected planar graphs is generalized to orientable surface.
基金Supported by the National Natural Science Foundation of China (69973001)
文摘A near-triangulation is such a connected planar graph whose inner faces are all triangles but the outer face may be not. Let G be a near-triangulation of order n and C be an SCDC (small circuit double cover)[2] of G. Let Then, C0 is said to he an equilibrium SCDC of G. In this paper, we show that if G is an outer planar graph, δ(C0)≤2, otherwiseδ(C0) ≤4.