init commit

2026-08-04 06:58:30 -06:00
commit 2b551e1e3a
7 changed files with 865 additions and 0 deletions
@@ -0,0 +1,114 @@
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Font;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+
+import javax.swing.JPanel;
+import javax.swing.text.Position;
+
+import edu.princeton.cs.algs4.Edge;
+
+public class DisplayPanel extends JPanel {
+
+    private static ST<Integer, Vertex> st;
+    private int n;
+    private static final int SIZE = 256;
+    private int a = SIZE / 2;
+    private int b = a;
+    private int r = 4 * SIZE / 5;
+
+    public DisplayPanel() {
+        super();
+            setPreferredSize(new Dimension(300, 300));
+            setSize(getPreferredSize());
+    }
+
+    @Override
+    protected void paintComponent(Graphics g) {
+        st = new ST<>();
+        EdgeWeightedGraph G = GraphFunctions.getGraph();
+        for(int v = 0; v < G.V(); v++)
+            st.put(v, new Vertex(v));
+        n = st.size();
+        // draw the entire graph first
+
+        Graphics2D g2d = (Graphics2D) g;
+        g2d.setRenderingHint(
+            RenderingHints.KEY_ANTIALIASING,
+            RenderingHints.VALUE_ANTIALIAS_ON);
+        g2d.setColor(Color.WHITE);
+        a = getWidth() / 2;
+        b = getHeight() / 2;
+        int m = Math.min(a, b);
+        r = 4 * m / 5;
+        int r2;
+        if(n > 0) r2 = Math.abs(m - r) / n;
+        else r2 = Math.abs(m - r) / 2;
+        for (int i = 0; i < n; i++) {
+            double t = 2 * Math.PI * i / n;
+            int x = (int) Math.round(a + r * Math.cos(t));
+            int y = (int) Math.round(b + r * Math.sin(t));
+            g2d.fillOval(x - r2, y - r2, 2 * r2, 2 * r2);
+            st.put(i, new Vertex(x, y));
+        }
+
+        g.getFont().deriveFont(Font.BOLD);
+        g2d.setColor(Color.ORANGE);
+        if(n < 50) {
+            for(int i = 0; i < n; i++) {
+                int x = st.get(i).getX();
+                int y = st.get(i).getY();
+
+                g.drawString(i + "", x - (2 * r2), y + (2 * r2));
+            }
+        }
+
+        drawLine(r2, g, g2d, G.edges(), Color.WHITE);
+        drawLine(r2, g, g2d, GraphFunctions.getMST(), Color.GREEN);
+    }
+
+    private void drawLine(int r2, Graphics g, Graphics2D g2d, Iterable<Edge> edges, Color color) {
+        g2d.setColor(color);
+        for (Edge e: edges) {
+            int v = e.either();
+            int w = e.other(v);
+
+            int vX = st.get(v).getX();
+            int wX = st.get(w).getX();
+            int vY = st.get(v).getY();
+            int wY = st.get(w).getY();
+
+            g.drawLine(vX, vY, wX, wY);
+            g.drawString(String.format("%.0f", e.weight()), ((vX + wX) / 2) + r2, ((vY + wY) / 2) + r2);
+        }
+    }
+
+    private class Vertex { // extends JComponent for @Override of paint()?
+        private int x;
+        private int y;
+        private int v;
+
+        public Vertex(int v) {
+            this.v = v;
+        }
+
+        public Vertex(int x, int y) {
+            this.x = x;
+            this.y = y;
+        }
+
+        public int getX() {
+            return x;
+        }
+
+        public int getY() {
+            return y;
+        }
+
+        public int getV() {
+            return v;
+        }
+    }
+}