reformat code

realDuYuanChao · realDuYuanChao · commit e5a3e4b47913 · 2020-09-22T10:09:04.000+08:00
diff --git a/DynamicProgramming/SubsetSum.java b/DynamicProgramming/SubsetSum.java
@@ -2,15 +2,27 @@
 
 public class SubsetSum {
 
-    /*
-    This algorithm will determine if a set of integers contains
-    a subset that sum to a given integer. The algorithm will
-    return true if such a subset exists and false otherwise.
-    This is a dynamic programming implementation.
+    /**
+     * Driver Code
      */
+    public static void main(String[] args) {
+        int[] arr = new int[]{50, 4, 10, 15, 34};
+        assert subsetSum(arr, 64); /* 4 + 10 + 15 + 34 = 64 */
+        assert subsetSum(arr, 99); /* 50 + 15 + 34 = 99 */
+        assert !subsetSum(arr, 5);
+        assert !subsetSum(arr, 66);
+    }
 
-    private static boolean subsetSum(int arr[], int n, int sum){
-        boolean isSum[][] = new boolean[n + 2][sum + 1];
+    /**
+     * Test if a set of integers contains a subset that sum to a given integer.
+     *
+     * @param arr the array contains integers.
+     * @param sum target sum of subset.
+     * @return {@code true} if subset exists, otherwise {@code false}.
+     */
+    private static boolean subsetSum(int[] arr, int sum) {
+        int n = arr.length;
+        boolean[][] isSum = new boolean[n + 2][sum + 1];
 
         isSum[n + 1][0] = true;
         for (int i = 1; i <= sum; i++) {
@@ -31,27 +43,4 @@ private static boolean subsetSum(int arr[], int n, int sum){
 
         return isSum[1][sum];
     }
-
-    /*
-    This is a driver method to run the algorithm with four
-    test values: the first two should evaluate true, and the
-    last two should evaluate false.
-     */
-    public static void main(String args[]) {
-        int arr[] = new int[]{50, 4, 10, 15, 34};
-        int n = arr.length;
-        // 4 + 10 + 15 + 34 = 64
-        int sum1 = 64;
-        // 50 + 15 + 34 = 99
-        int sum2 = 99;
-        // No subset of the given array will give a sum
-        //  of 5 or 66
-        int sum3 = 5;
-        int sum4 = 66;
-
-        System.out.println(subsetSum(arr, n, sum1));
-        System.out.println(subsetSum(arr, n, sum2));
-        System.out.println(subsetSum(arr, n, sum3));
-        System.out.println(subsetSum(arr, n, sum4));
-    }
 }
