Problem I. Floyd-Warshall

Author:StdAlg   Time limit:1 sec
Input file:input.txt   Memory limit:8 Mb
Output file:output.txt  


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.

Sample tests

No. Input file (input.txt) Output file (output.txt)
3 3
1 2 5
1 3 10
2 3 2
0 5 7
  0 2

0.083s 0.012s 13