From f45a13dde742936783ad0497381c8b633d4d84de Mon Sep 17 00:00:00 2001
From: josch <j.schauer@email.de>
Date: Thu, 11 Apr 2013 10:18:03 +0200
Subject: [PATCH] read edges from stdin instead of argv

---
 README.md                                    | 20 +++++++++++++-------
 de/normalisiert/utils/graphs/TestCycles.java | 14 +++++++++-----
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 0d0ecc2..483928b 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ Usage
 -----
 
     make
-    java de.normalisiert.utils.graphs.TestCycles 4 0,1 0,2 1,0 1,3 2,0 3,0 3,1 3,2
+    echo "0 1\n0 2\n1 0\n1 3\n2 0\n3 0\n3 1\n3 2" | java de.normalisiert.utils.graphs.TestCycles 4
 
 First argument is the number of vertices. Subsequent arguments are ordered
 pairs of comma separated vertices that make up the directed edges of the
@@ -24,12 +24,13 @@ For simplicity, there is no DOT file parser included but the following allows
 to create a suitable argument string for simple DOT graphs.
 
 Given a DOT file of a simple (no labels, colors, styles, only pairs of
-vertices...) directed graph, the following line produces commandline
-arguments in the above format for that graph.
+vertices...) directed graph, the following lines generate the number of
+vertices as well as the edge list expected on standard input.
 
-	echo `sed -n -e '/^\s*[0-9]\+;$/p' graph.dot | wc -l` `sed -n -e 's/^\s*\([0-9]\) -> \([0-9]\);$/\1,\2/p' graph.dot`
+        sed -n -e '/^\s*[0-9]\+;$/p' graph.dot | wc -l
+        sed -n -e 's/^\s*\([0-9]\) -> \([0-9]\);$/\1 \2/p' graph.dot
 
-The above line works on DOT files like the following:
+The above lines work on DOT files like the following:
 
     digraph G {
       0;
@@ -42,6 +43,11 @@ The above line works on DOT files like the following:
       2 -> 1;
       }
 
-It would produce the following output:
+They would produce the following output:
 
-    3 0,1 0,2 1,0 2,0 2,1
+    3
+    0 1
+    0 2
+    1 0
+    2 0
+    2 1
diff --git a/de/normalisiert/utils/graphs/TestCycles.java b/de/normalisiert/utils/graphs/TestCycles.java
index 6e636e3..a952df8 100644
--- a/de/normalisiert/utils/graphs/TestCycles.java
+++ b/de/normalisiert/utils/graphs/TestCycles.java
@@ -2,6 +2,7 @@ package de.normalisiert.utils.graphs;
 
 
 import java.util.List;
+import java.io.*;
 
 
 /**
@@ -15,9 +16,9 @@ public class TestCycles {
 	/**
 	 * @param args
 	 */
-	public static void main(String[] args) {
-		if (args.length < 2) {
-			System.out.println("usage: de.normalisiert.utils.graphs.TestCycles num_vertices [v1,v2...]");
+	public static void main(String[] args) throws java.io.IOException {
+		if (args.length != 1) {
+			System.out.println("usage: echo \"v1 v2\nv1 v3\n...\" | de.normalisiert.utils.graphs.TestCycles num_vertices");
 			System.exit(1);
 		}
 
@@ -43,8 +44,11 @@ public class TestCycles {
 		adjMatrix[7][9] = true;
 		adjMatrix[9][6] = true;*/
 		
-		for (int i = 1; i < args.length; i++) {
-			String[] vertices = args[i].split(",", 2);
+		BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
+		String line;
+
+		while ((line = stdin.readLine()) != null && line.length()!= 0) {
+			String[] vertices = line.split(" ", 2);
 			int v1 = Integer.parseInt(vertices[0]);
 			int v2 = Integer.parseInt(vertices[1]);
 			adjMatrix[v1][v2] = true;