Azerbaijan Programming Olympiad - 2nd Stage preparation
Diameter of the graph
The connected weighted and notoriented graph is given.
Consider the pair of vertices, for which the distance between them is maximum among all pairs of vertices. Such distance is called the graph diameter. The eccentricity of the vertex v is the maximal distance from the vertex v to all other vertices of the graph. The radius of the graph is minimal eccentricity of the vertices.
Find the diameter and the radius of the graph.
The first line contains the number of graph vertices n (1 ≤ n ≤ 100). Each of the next n lines contains n numbers - the adjacency matrix of the graph, where -1 means the absence of the edge between the vertices, and any nonnegative integer means the edge with the given weight. The main diagonal of the matrix contains zeros; the edge weights do not exceed 1000.
Print two numbers: the diameter and the radius of the graph.
4 0 -1 1 2 -1 0 -1 5 1 -1 0 4 2 5 4 0