Channel routing problem is a key problem in the design of VLSI ships. In this paper, based on two kinds of constraint graph of nodes, two routing algorithms including a pair of and two pairs of empty nodes can be designed to solve the vertical constraint graph problems. The better width can be obtained by using the proposed methods.%通道布线问题是VLSI物理设计中的一个关键问题，本文从结点的两类约束图入手来研究布线算法。对垂直约束图中含有有向圈的一类通道布线问题进行研究，设计出包含一对和两对空结点情况下的布线算法，该方法能够得到更好的轨道高度。
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