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package bjc.utils.graph;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
import java.util.stream.IntStream;
public class AdjacencyMap<T> {
private Map<T, Map<T, Integer>> adjMap;
public AdjacencyMap(Set<T> vertices) {
vertices.forEach(src -> {
Map<T, Integer> srcRow = new HashMap<>();
vertices.forEach(tgt -> srcRow.put(tgt, 0));
adjMap.put(src, srcRow);
});
}
public boolean isDirected() {
GenHolder<Boolean> res = new GenHolder<>(true);
adjMap.entrySet()
.forEach(src -> src.getValue().entrySet().forEach(tgt -> {
int lhs = tgt.getValue();
int rhs = adjMap.get(tgt.getKey()).get(src.getKey());
if (lhs != rhs) {
res.held = false;
}
}));
return res.held;
}
public void setWeight(T src, T tgt, int weight) {
adjMap.get(src).put(tgt, weight);
}
public Graph<T> toGraph() {
Graph<T> ret = new Graph<>();
adjMap.entrySet()
.forEach(src -> src.getValue().entrySet()
.forEach(tgt -> ret.addEdge(src.getKey(),
tgt.getKey(), tgt.getValue())));
return ret;
}
public static AdjacencyMap<Integer> fromStream(InputStream stream) {
Scanner scn = new Scanner(stream);
scn.useDelimiter("\n");
// First, read in number of vertices
int numVertices = Integer.parseInt(scn.next());
Set<Integer> vertices = new HashSet<>();
IntStream.range(0, numVertices).forEach(e -> vertices.add(e));
// Create the adjacency map
AdjacencyMap<Integer> aMap = new AdjacencyMap<>(vertices);
GenHolder<Integer> row = new GenHolder<>(0);
scn.forEachRemaining((strang) -> {
String[] parts = strang.split(" ");
int col = 0;
for (String part : parts) {
aMap.setWeight(row.held, col, Integer.parseInt(part));
col++;
}
row.held++;
});
scn.close();
return aMap;
}
public void toStream(OutputStream os) {
PrintStream ps = new PrintStream(os);
adjMap.entrySet().forEach(src -> {
src.getValue().entrySet()
.forEach(tgt -> ps.printf("%d ", tgt.getValue()));
ps.println();
});
ps.close();
}
}
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