摘要: We consider worst case time bounds for NP-complete problems including 3-coloring, 3-edge-coloring, and 3-list-coloring. Our algorithms are based on a common generalization of these problems, called symbol-system satisfiability or, briefly, SSS. 3-SAT is equivalent to (2,3)-SSS while the other above special cases (3,2)-SSS; there also natural duality transformation from (a,b)-SSS (b,a)-SSS. give fast algorithm (3,2)-SSS use it improve solving listed above.