SPFA算法大致流程是用一个队列来进行维护。初始时将源点加入队列，每次

The general process of the SPFA algorithm is to use a queue for maintenance. Initially, the source point is added to the queue, one element at a time is taken from the queue, and all the points adjacent to it are relaxed. If a neighboring point is relaxed, it is added to the queue. The algorithm ends when the queue is empty.

The General process of the SPFA algorithm is to be maintained in a queue. The source point is initially joined into the queue, one element is removed from the queue at a time, and all points adjacent to it are relaxed, and if an adjacent point is relaxed successfully, it is added to the queue. The algorithm ends until the queue is empty.

The general process of SPFA algorithm is to use a queue for maintenance. At the beginning, the source point is added to the queue, one element is taken out of the queue each time, and all points adjacent to it are relaxed. If a point adjacent to it is relaxed successfully, it is added to the queue. Until the end of the empty queue algorithm.<br>