Update Average.java

drabbit75 · drabbit75 · commit 94a65964d890 · 2020-08-18T09:50:59.000+08:00
1. add int type array
2. The equality of floating-point numbers should be judged by the absolute value of the difference less than a small number
diff --git a/Maths/Average.java b/Maths/Average.java
@@ -4,10 +4,13 @@
  * Calculate average of a list  of numbers
  */
 public class Average {
+    private static final double SMALL_VALUE = 0.00001f;
     public static void main(String[] args) {
-        assert average(new double[]{3, 6, 9, 12, 15, 18, 21}) == 12;
-        assert average(new double[]{5, 10, 15, 20, 25, 30, 35}) == 20;
-        assert average(new double[]{1, 2, 3, 4, 5, 6, 7, 8}) == 4.5;
+        assert Math.abs(average(new double[]{3, 6, 9, 12, 15, 18, 21}) - 12) < SMALL_VALUE;
+        assert Math.abs(average(new double[]{5, 10, 15, 20, 25, 30, 35}) - 20) < SMALL_VALUE;
+        assert Math.abs(average(new double[]{1, 2, 3, 4, 5, 6, 7, 8}) - 4.5) < SMALL_VALUE;
+        int[] array = {2, 4, 10};
+        assert average(array) == 5;
     }
 
     /**
@@ -23,4 +26,19 @@ public static double average(double[] numbers) {
         }
         return sum / numbers.length;
     }
-}
+    
+    /**
+     * find average value of int array
+     *
+     * @param array the array contains element and the sum does not 
+     * excess long value limit
+     * @return average value
+     */
+    public static int average(int[] array) {
+        long sum = 0;
+        for (int i = 0 ; i < array.length; ++i) {
+            sum += array[i];
+        }
+        return (int)(sum / array.length);
+    }
+}
