优先队列的使用使用优先队列，首先要包函STL头文件"queue"，以一个例子来解释吧(呃，写完才发现，这个代码包函了几乎所有我们要用到的用法。-The use of priority queue using a priority queue, we must first package the letter STL header file "queue", an example to explain it (uh, finished only to find the code package letter almost all of what we need to use.