|| ||Code Submission Evaluation System
CSES Problem Set
Task | Statistics
CSES - Edge DirectionsCSES - Edge Directions
|Time limit:||1.00 s
||Memory limit:||512 MB|
Given an undirected graph, your task is to choose a direction for each edge so that the resulting directed graph is acyclic.
The first input line has two integers $n$ and $m$: the number of nodes and edges. The nodes are numbered $1,2,\dots,n$.
After this, there are $m$ lines describing the edges. Each line has two distinct integers $a$ and $b$: there is an edge between nodes $a$ and $b$.
Print $m$ lines describing the directions of the edges. Each line has two integers $a$ and $b$: there is an edge from node $a$ to node $b$. You can print any valid solution.
- $1 \le n \le 10^5$
- $1 \le m \le 2 \cdot 10^5$
- $1 \le a,b \le n$