Problem 4.6 TADM

shekhargulati · shekhargulati · commit a03755f0d0da · 2016-04-02T23:41:53.000+05:30
diff --git a/java8/src/main/java/com/shekhargulati/tadm/ch04/excercises/Problem4_6.java b/java8/src/main/java/com/shekhargulati/tadm/ch04/excercises/Problem4_6.java
@@ -0,0 +1,23 @@
+package com.shekhargulati.tadm.ch04.excercises;
+
+import java.util.Arrays;
+
+public class Problem4_6 {
+
+    public static boolean findPair(int[] s1, int[] s2, int x) {
+        /*
+            Sort one array let say s2
+            for each el in s1
+               do a binary search in s2 for x-el
+               if found return el and (x-el)
+         */
+        Arrays.sort(s2);
+        for (int f : s1) {
+            int s = x - f;
+            if (Arrays.binarySearch(s2, s) >= 0) {
+                return true;
+            }
+        }
+        return false;
+    }
+}
diff --git a/java8/src/test/java/com/shekhargulati/tadm/ch04/excercises/Problem4_6Test.java b/java8/src/test/java/com/shekhargulati/tadm/ch04/excercises/Problem4_6Test.java
@@ -0,0 +1,14 @@
+package com.shekhargulati.tadm.ch04.excercises;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+public class Problem4_6Test {
+
+    @Test
+    public void shouldFindAPair() throws Exception {
+        boolean pair = Problem4_6.findPair(new int[]{4, 3, 7}, new int[]{3, 2, 1}, 5);
+        assertTrue(pair);
+    }
+}
