Intractable is the problem of finding two link-disjoint paths of minimal cost if the path cost is limited since it can be a special case of the partition problem. In optical networks, this limit can be introduced by the signal modulation reach. Even without this limit, the existing literature suggested the problem intractable because of the spectrum continuity and contiguity constraints, but we show that the problem can be solved exactly with the recently-proposed generic Dijkstra algorithm over a polynomially-bounded search space, thus proving the problem tractable.

翻译：当路径成本受限时，寻找两条成本最小的链路不相交路径是难解问题，因为该问题可视为划分问题的一个特例。在光网络中，信号调制距离可能引入这种限制。即使没有这一限制，现有文献也认为由于频谱连续性和相邻性约束，该问题仍属难解。但研究表明，通过近期提出的通用Dijkstra算法，可在多项式有界搜索空间内精确求解该问题，从而证明其易解性。