Directed Acyclic Graph

Given a directed graph, output YES if it is acyclic, and NO otherwise.

Input

As usual.
N ≤ 1000.

Output

YES or NO.

Sample Input

3
0 1 0 
0 0 1
1 0 0

Sample Output

NO

Sample Input 2

3
0 1 0
0 0 1
0 0 0

Sample Output 2

YES

All Submissions
Best Solutions


Point Value: 10
Time Limit: 2.00s
Memory Limit: 16M
Added: Jun 28, 2013

Problem Types: [Show]

Languages Allowed:
C++03, PAS, C, HASK, ASM, RUBY, PYTH2, JAVA, PHP, SCM, CAML, PERL, C#, C++11, PYTH3

Comments (Search)

Not sure why my most recent submission fails on the 3rd test case. I've been trying to figure out why... am I missing something? My code works on everything I've tried so far.

First number is the number of edges, but for each edge, what does the third number stand for?

This is the correct interpretation of the input.
http://wcipeg.com/wiki/Graph_theory#Adjacency_matrix

As usual -> see graph2p1.