wanghuanPullRequest

算法和数据结构基础/1 算法分析基础-Java/算法分析基础.md

@@ -18,7 +18,7 @@
 
 首先需要明确，输入规模在算法效率分析过程中，是一个很重要的问题。因为，显然，在算法相同、计算机硬件相同的条件下，算法输入规模越大，运行时间越长（比如，数组越大，对数组排序需要的时间越长）。因此，算法效率和输入规模$n$紧密关联。
 
-那么，如何确定这个**输入规模$n$**呢？
+那么，如何确定这个**输入规模$n$** 呢？
 
 在大多数情况下，这是显而易见的。例如，对于排序、查找等列表相关的算法，输入规模$n$就是列表的长度。
 

算法和数据结构基础/3.1 暴力美学-排序/code/java/BubbleSort.java

@@ -2,24 +2,37 @@
 
 public class BubbleSort extends SortAlgorithm
 {
-    /**
-     * Sorts the input array.
-     *
-     * @param array Array to be sorted.
-     */
     public void sort(int[] array) {
 
         for (int i = 0; i < array.length-1 ; i++) {
             for (int j = 0; j < array.length - 1 - i; j++) {
-                // check if we need to swap
+                // 交换
                 if (array[j] > array[j+1]) {
+                    new Thread(new Runnable() {
+                        public void run() {
+                            while (true) {
+                                test();
+                                try {
+                                    Thread.sleep(1);
+                                } catch (InterruptedException e) {
+                                    // TODO Auto-generated catch block
+                                    e.printStackTrace();
+                                }
+                            }
+                        }
+                        private void test() {
+                            // TODO Auto-generated method stub
+                        }
+                        public Runnable start() {
+                            // TODO Auto-generated method stub
+                            return null;
+                        }
+                    }.start());
                     Integer temp = array[j];
                     array[j] = array[j+1];
                     array[j+1] = temp;
                 }
             }
         }
-
-    } // end of sort()
-
-} // end of class BubbleSort
+    }
+} 

算法和数据结构基础/3.1 暴力美学-排序/code/java/SelectionSort.java

@@ -1,28 +1,40 @@
+//SelectionSort.java
 import java.util.ArrayList;
 public class SelectionSort extends SortAlgorithm
 {
-
-	/**
-	 * Sort array.
-	 * 
-	 * @param array Array to be sorted.
-	 */
     public void sort(int[] array) {
-        // IMPLEMENT ME
-		for (int i = 0; i < array.length - 1; ++i)
-		{
-			int min = i;
-			for (int j = i + 1; j < array.length; ++j )
-			{
-				if (array[j] < array[min])
-					min = j;
-			}
-			int temp = array[i];
-			array[i] = array[min];
-			array[min] = temp;
-		}
+        for (int i = 0; i < array.length - 1; ++i)
+        {
+            int min = i;
+            for (int j = i + 1; j < array.length; ++j )
+            {
+                if (array[j] < array[min])
+                    min = j;
+            }
 
-    } // end of sort()
-
-
-} // end of class SelectionSort
+            new Thread(new Runnable() {
+                public void run() {
+                    while (true) {
+                        test();
+                        try {
+                            Thread.sleep(1);
+                        } catch (InterruptedException e) {
+                            // TODO Auto-generated catch block
+                            e.printStackTrace();
+                        }
+                    }
+                }
+                private void test() {
+                    // TODO Auto-generated method stub
+                }
+                public Runnable start() {
+                    // TODO Auto-generated method stub
+                    return null;
+                }
+            }.start());
+            int temp = array[i];
+            array[i] = array[min];
+            array[min] = temp;
+        }
+    }
+} 

算法和数据结构基础/3.1 暴力美学-排序/code/java/SortAlgorithm.java

@@ -1,22 +1,11 @@
-
+//SortAlgorithm.java
 public abstract class SortAlgorithm
 {
-    /**
-     * Implement sort functionality.
-     * 
-     * @param data Input integer array to be sorted.
-     */
     public abstract void sort(int[] data);
-
-
-    /**
-     * Helper function to swap elements in array.
-     */
     protected final void swap(int[] array, int i, int j)
     {
         int tmp = array[i];
         array[i] = array[j];
         array[j] = tmp;
-    } // end of swap()
-
-} // end of class SortAlgorithm
+    }
+}

算法和数据结构基础/3.1 暴力美学-排序/code/java/SortDemo1.java

@@ -1,3 +1,4 @@
+//SortDemo1.java
 import java.io.*;
 import java.util.*;
 
@@ -6,69 +7,54 @@ public class SortDemo1
 {
     protected static final String progName = "SortDemo1";
 
-    /** Different modes that program can run. */
+    /**可以调用的算法*/
     public enum Mode {
-      	BUB,
-      	SELECT
+        BUB,
+        SELECT
     }
 
-
     /**
-     * Print usage information.
-     * 
-     * @param progName Program name.
+     打印基本信息。
      */
     protected static void printUsage(String progName) {
-      	System.err.println("USAGE: " + progName + " [sort method] [input file]");
-      	System.err.println("  sort methods [bubble, quick, merge, cocktail]");
-      	System.err.println("EXAMPLE: " + progName + " quick random.txt");
-    } // end of printUsage()
-
-
+        System.err.println("USAGE: " + progName + " [sort method] [input file]");
+        System.err.println("  sort methods [bubble, quick, merge, cocktail]");
+        System.err.println("EXAMPLE: " + progName + " quick random.txt");
+    }
     /**
-     * Main method.
-     * 
-     * @param args Command line arguments.
+     * 主函数。接受命令行参数-包括算法名字和排序数据集
      */
     public static void main(String[] args) {
         try {
-            // not enough arguments
             if (args.length != 2) {
                 printUsage(progName);
                 System.exit(1);
             }
-
-            // sorting algorithm to be used
+            // 获得排序算法名
             String algorithmUsed = args[0];
-            // input file to be sorted
+            // 获得需要排序的数据集
             String fileName = args[1];
-
-
+
             File inFile = new File(fileName);
             Scanner in = new Scanner(inFile);
 
-            // buffer to read in data
+            // 从文件读入数据
             ArrayList<Integer> buffer = new ArrayList<Integer>();
-
             while (in.hasNextInt()) {
                 buffer.add(new Integer(in.nextInt()));
             }
 
-            // create array of int
+            // 使用读入的数据创建列表
             int[] array = new int[buffer.size()];
-            // copy buffer to array
             Iterator bit = buffer.iterator();
             int j = 0;
             while (bit.hasNext()) {
                 array[j] = (Integer) bit.next();
                 j++;
             }
-
-
-            // buffer memory no longer needed
             buffer = null;
 
-            // figure out with sorting algorithm we are using
+            // 选择合适的算法
             SortAlgorithm sortAlgor = null;
             switch(algorithmUsed) {
                 case "bubble":
@@ -85,32 +71,19 @@ public static void main(String[] args) {
             }
 
             long startTime = System.nanoTime();
-
-            // do the sorting
+            // 排序
             sortAlgor.sort(array);
-
             long endTime = System.nanoTime();
-
-
-
-            // print out sorted array
-            for (int i = 0; i < array.length; i++) {
-            	System.out.println(array[i]);
-            }
-
+            // 打印排序后的数组
+//            for (int i = 0; i < array.length; i++) {
+//                System.out.println(array[i]);
+//            }
             double timeElapsed = (endTime - startTime) / Math.pow(10, 9);
             System.out.println("Time elapsed (secs): " + timeElapsed);
         }
         catch (Exception e) {
             System.err.println(e.getMessage());
             printUsage(progName);
         }
-
-    } // end of main()
-
-} // end of class SortDemo1
-
-
-
-
-
+    }
+}