有N个城市，编号为0、1…N-1，每个城市之间的路径长度保存在二位数组a中，如a[i][j]表示城市i与城市j的路径长度。求某个城市到其余城市的最短路径。-cities are N, No. 0,1 ... N-1, every city path length between the two kept in a group median, if a [i] [j] i said cities and urban j length of the path. For a city to the other cities in the shortest path.