You are to write a program that finds shortest distances between all pairs
of vertices in a directed weighted graph.
Graph consists of N vertices, numbered from 1 to N, and M edges.
Input file format
Input file contains two integers N and M, followed my M triplets of integers
ui vi wi — starting vertex, ending vertex and weight or the edge.
There is at most one edge connecting two vertices in every direction. There are no cycles of negative weight.
Output file format
Output file must contain a matrix of size NxN.
Element in the j-th column of i-th row mush be the shortest distance between
vertices i and j.
The distance from the vertex to itself is considered to be 0.
If some vertex is not reachable from some other,
there must be empty space in corresponding cell of matrix.
0 ≤ N ≤ 100.
All weights are less than 1000 by absolute value.