add a new file to visual trace

src/main/java/edu/princeton/cs/algs4/TraceInsertion.java

@@ -0,0 +1,110 @@
+
+
+/******************************************************************************
+ *  Compilation:  javac TraceInsertion.java
+ *  Execution:    java  TraceInsertion input
+ *  Dependencies: StdDraw.java
+ *
+ *  Inserstion sort the sequence of strings specified on the command-line
+ *  and show the detailed trace.
+ *
+ *  % java TraceInsertion SORTEXAMPLE
+ *
+ ******************************************************************************/
+package edu.princeton.cs.algs4;
+
+import java.awt.Font;
+
+public class TraceInsertion {
+
+    // insertion sort
+    public static void sort(String[] a) {
+        int n = a.length;
+        for (int i = 0; i < n; i++) {
+            int j;
+            for (j = i; j > 0 && less(a[j], a[j-1]); j--) {
+                exch(a, j, j-1);
+            }
+            draw(a, i, i, j);
+        }
+    }
+
+
+    // exchange a[i] and a[j]
+    private static void exch(String[] a, int i, int j) {
+        String swap = a[i];
+        a[i] = a[j];
+        a[j] = swap;
+    }
+
+    // is v < w ?
+    private static boolean less(String v, String w) {
+        return v.compareTo(w) < 0;
+    }
+
+    private static void draw(String[] a, int row, int ith, int jth) {
+        StdDraw.setPenColor(StdDraw.BLACK);
+        StdDraw.text(-2.50, row, ith + "");
+        StdDraw.text(-1.25, row, jth + "");
+        for (int i = 0; i < a.length; i++) {
+            if (i == jth)      StdDraw.setPenColor(StdDraw.BOOK_RED);
+            else if (i > ith)  StdDraw.setPenColor(StdDraw.LIGHT_GRAY);
+            else if (i < jth)  StdDraw.setPenColor(StdDraw.LIGHT_GRAY);
+            else               StdDraw.setPenColor(StdDraw.BLACK);
+            StdDraw.text(i, row, a[i]);
+        }
+    }
+
+    // display header
+    private static void header(String[] a) {
+        int n = a.length;
+
+        StdDraw.setPenColor(StdDraw.BLACK);
+        StdDraw.text(n/2.0, -3, "a[ ]");
+        for (int i = 0; i < n; i++)
+            StdDraw.text(i, -2, i + "");
+        StdDraw.text(-2.50, -2, "i");
+        StdDraw.text(-1.25, -2, "j");
+        StdDraw.setPenColor(StdDraw.BOOK_RED);
+        StdDraw.line(-3, -1.65, n - 0.5, -1.65);
+        StdDraw.setPenColor(StdDraw.BLACK);
+        for (int i = 0; i < n; i++)
+            StdDraw.text(i, -1, a[i]);
+    }
+
+    // display footer
+    private static void footer(String[] a) {
+        int n = a.length;
+        StdDraw.setPenColor(StdDraw.BLACK);
+        for (int i = 0; i < n; i++)
+            StdDraw.text(i, n, a[i]);
+    }
+
+
+
+    // test client
+    public static void main(String[] args) {
+        // parse command-line argument as an array of 1-character strings
+        String s = args[0];
+        int n = s.length();
+        String[] a = new String[n];
+        for (int i = 0; i < n; i++)
+            a[i] = s.substring(i, i+1);
+
+        // set canvas size
+        StdDraw.setCanvasSize(30*(n+3), 30*(n+3));
+        StdDraw.setXscale(-3, n+1);
+        StdDraw.setYscale(n+1, -3);
+        StdDraw.setFont(new Font("SansSerif", Font.PLAIN, 13));
+
+        // draw the header
+        header(a);
+
+        // sort the array
+        sort(a);
+
+        // draw the footer
+        footer(a);
+    }
+
+}