翻译成英文:Discuss with variable span and the constraints of X pattern matching problem, which extends therange of variable span effect of wildcards, X condition defines a matching number of textcharacters, forming a large and sparse candidate solution Description through the form, the input text, patterns and variable span is transformed into a directed acyclic graph structure, and prove that the graph structure in the path from the top layer to the bottom layer which is a collection of candidate solution space, the path subset independent of each other as the matching solution Then we give a graph structure of the path search Algorithm alternately pruning and search, use the preorder traversal delete redundant nodes, and according to the node's locationinformation and share information to choose the The experimental part adopts the matchingloss rate metrics of the completeness of the solution set of the solution, the results show that the algorithm with the heuristic algorithm can be complementary, effectively reduce the matching solution loss