aboutsummaryrefslogtreecommitdiff
path: root/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java
diff options
context:
space:
mode:
authorJonas Smedegaard <dr@jones.dk>2025-04-29 08:09:28 +0200
committerJonas Smedegaard <dr@jones.dk>2025-04-29 08:09:28 +0200
commit3738c1fc8b2fa92b819b1ff948b3b39de60757b7 (patch)
treec5db7a878770da6c8180cc468184712d585b0d88 /src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java
parent794be4694f1a1fa36d87543aab840331c6d39745 (diff)
always use brace in for- and if-construct
Diffstat (limited to 'src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java')
-rw-r--r--src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java74
1 files changed, 50 insertions, 24 deletions
diff --git a/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java b/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java
index 6b47bd2..5c0dd80 100644
--- a/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java
+++ b/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java
@@ -40,8 +40,9 @@ public class GraphAlgorithms {
/// @return boolean
public static boolean isPath(final List<Edge> edges) {
for (int i = 1; i < edges.size(); i++) {
- if (edges.get(i - 1).to() != edges.get(i).from())
+ if (edges.get(i - 1).to() != edges.get(i).from()) {
return false;
+ }
}
return true;
@@ -58,8 +59,9 @@ public class GraphAlgorithms {
int length = 0;
for (int i = 1; i < path.size(); i++) {
Integer w = g.getWeight(path.get(i - 1),path.get(i));
- if (w == null)
+ if (w == null) {
return null;
+ }
length += w;
}
@@ -79,10 +81,12 @@ public class GraphAlgorithms {
/// @return int
static int cmpEdgeWeight(final Edge e1, final Edge e2) {
int w1 = e1.weight(), w2 = e2.weight();
- if (w1 != w2)
+ if (w1 != w2) {
return w1 - w2;
- if (e1.from() != e2.from())
+ }
+ if (e1.from() != e2.from()) {
return e1.from().name().compareTo(e2.from().name());
+ }
return e1.to().name().compareTo(e2.to().name());
}
@@ -95,11 +99,13 @@ public class GraphAlgorithms {
/// @param e2 foo
/// @return int
static int cmpEdgeFrom(final Edge e1, final Edge e2) {
- if (e1.from() != e2.from())
+ if (e1.from() != e2.from()) {
return e1.from().name().compareTo(e2.from().name());
+ }
int w1 = e1.weight(), w2 = e2.weight();
- if (w1 != w2)
+ if (w1 != w2) {
return w1 - w2;
+ }
return e1.to().name().compareTo(e2.to().name());
}
@@ -112,10 +118,12 @@ public class GraphAlgorithms {
/// @param e2 foo
/// @return int
static int cmpEdgeTo(final Edge e1, final Edge e2) {
- if (e1.to() != e2.to())
+ if (e1.to() != e2.to()) {
return e1.to().name().compareTo(e2.to().name());
- if (e1.from() != e2.from())
+ }
+ if (e1.from() != e2.from()) {
return e1.from().name().compareTo(e2.from().name());
+ }
int w1 = e1.weight(), w2 = e2.weight();
return w1 - w2;
@@ -186,13 +194,16 @@ public class GraphAlgorithms {
//System.out.println("visited " + w);
visited.add(w);
Collection<Edge> outedge = g.outEdge(w);
- if (outedge == null)
+ if (outedge == null) {
continue;
+ }
for (Edge e: outedge) {
- if (visited.contains(e.to()))
+ if (visited.contains(e.to())) {
continue;
- if (thisLevel.contains(e.to()))
+ }
+ if (thisLevel.contains(e.to())) {
continue;
+ }
nextLevel.add(e.to());
}
}
@@ -222,12 +233,14 @@ public class GraphAlgorithms {
/// @param v foo
/// @param visited foo
private static void visitDepthFirst(final Graph g, final Vertex v, final Set<Vertex> visited) {
- if (visited.contains(v))
+ if (visited.contains(v)) {
return;
+ }
//System.out.println("visited "+v);
visited.add(v);
- for (Edge e: g.outEdge(v))
+ for (Edge e: g.outEdge(v)) {
visitDepthFirst(g, e.to(), visited);
+ }
}
/// an implementation of Prim's algorithm
@@ -247,15 +260,19 @@ public class GraphAlgorithms {
while (true) {
Edge nearest = null;
for (Edge e: edges) {
- if (!frontier.contains(e.from()))
+ if (!frontier.contains(e.from())) {
continue;
- if (frontier.contains(e.to()))
+ }
+ if (frontier.contains(e.to())) {
continue;
- if (nearest == null || nearest.weight() > e.weight())
+ }
+ if (nearest == null || nearest.weight() > e.weight()) {
nearest = e;
+ }
}
- if (nearest == null)
+ if (nearest == null) {
break;
+ }
mst.add(nearest);
frontier.add(nearest.to());
}
@@ -278,8 +295,9 @@ public class GraphAlgorithms {
HashSet<Vertex> done = new HashSet<>();
HashMap<Vertex,Edge> prev = new HashMap<>();
HashMap<Vertex,Integer> weight = new HashMap<>();
- for (Vertex w: g.vertices())
+ for (Vertex w: g.vertices()) {
weight.put(w, maxint);
+ }
// start node is done, distance 0 from start
weight.put(start, 0);
@@ -294,7 +312,9 @@ public class GraphAlgorithms {
for (Vertex w1:done) {
for (Edge e :g.outEdge(w1)) {
Vertex w2 = e.to();
- if (done.contains(w2)) continue;
+ if (done.contains(w2)) {
+ continue;
+ }
if ((weight.get(w1) + e.weight()) < neardist) {
nearest = e.to();
neardist = weight.get(w1) + e.weight();
@@ -305,7 +325,9 @@ public class GraphAlgorithms {
// System.out.println("find nearest "+done2near);
// if no more, then we are done
- if (nearest == null) break;
+ if (nearest == null) {
+ break;
+ }
// update distance from this node to other nodes
for (Edge e1 : g.outEdge(nearest)) {
@@ -338,11 +360,13 @@ public class GraphAlgorithms {
try {
BufferedReader in = new BufferedReader(new FileReader(file));
for (String line = in.readLine(); line != null; line = in.readLine()) {
- if (line.length() == 0)
+ if (line.length() == 0) {
continue;
+ }
String[] arr = line.split(",");
- if (arr.length != 3)
+ if (arr.length != 3) {
throw new RuntimeException("CSV file format error: " + line);
+ }
g.insertEdge(arr[0].trim(), arr[1].trim(), Integer.parseInt(arr[2].trim()));
g.insertEdge(arr[1].trim(), arr[0].trim(), Integer.parseInt(arr[2].trim()));
}
@@ -358,8 +382,9 @@ public class GraphAlgorithms {
public static void printGraph(final Graph g) {
for (Vertex v: sortVertex(g.vertices())) {
System.out.println(v.toString());
- for (Edge e: sortEdgesTo(g.outEdge(v)))
+ for (Edge e: sortEdgesTo(g.outEdge(v))) {
System.out.println(" " + e.toString());
+ }
}
}
@@ -389,8 +414,9 @@ public class GraphAlgorithms {
BufferedReader in = new BufferedReader(new FileReader(f));
while (true) {
String s = in.readLine();
- if (s == null)
+ if (s == null) {
break;
+ }
list.add(s);
}
in.close();