Merge pull request #161 from sir-gon/feature/a_very_big_sum

Feature/a very big sum

Author: sir-gon

algorithm-exercises-java/src/main/java/ae/hackerrank/VeryBigSum.java

@@ -0,0 +1,29 @@
+package ae.hackerrank;
+
+import java.util.List;
+
+/**
+ * VeryBigSum.
+ *
+ * @link Problem definition [[docs/hackerrank/warmup/a_very_big_sum.md]]
+ */
+public class VeryBigSum {
+
+  private VeryBigSum() {
+  }
+
+  static java.util.logging.Logger logger = util.CustomLogger.getLogger();
+
+  /**
+   * aVeryBigSum.
+   */
+  public static long aVeryBigSum(List<Long> ar) {
+    long total = 0L;
+
+    for (long x : ar) {
+      total += x;
+    }
+
+    return total;
+  }
+}

algorithm-exercises-java/src/test/java/ae/hackerrank/VeryBigSumTest.java

@@ -0,0 +1,23 @@
+package ae.hackerrank;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Arrays;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+
+class VeryBigSumTest {
+
+  @Test void test_aVeryBigSum() {
+
+    Long answer = 5000000015L;
+    List<Long> arr = Arrays.asList(1000000001L, 1000000002L, 1000000003L, 1000000004L, 1000000005L);
+
+    Long solutionFound = VeryBigSum.aVeryBigSum(arr);
+
+    assertEquals(answer, solutionFound,
+        String.format("Problem 0000 answer must be: %d", answer)
+    );
+  }
+}

config/checkstyle/checkstyle.xml

@@ -348,7 +348,7 @@
       <property name="excludeScope" value="nothing"/>
     </module>
     <module name="MethodName">
-      <property name="format" value="^[a-z][a-z0-9]\w*$"/>
+      <property name="format" value="(^[a-z]|[A-Z0-9])[a-z]*$"/>
       <message key="name.invalidPattern"
              value="Method name ''{0}'' must match pattern ''{1}''."/>
     </module>

docs/hackerrank/warmup/a_very_big_sum.md

@@ -0,0 +1,55 @@
+# [A Very Big Sum](https://www.hackerrank.com/challenges/a-very-big-sum)
+
+Difficulty: #easy
+Category: #warmup
+
+In this challenge, you are required to calculate and print the
+sum of the elements in an array, keeping in mind that some of
+those integers may be quite large.
+
+## Function Description
+
+Complete the aVeryBigSum function in the editor below.
+It must return the sum of all array elements.
+
+aVeryBigSum has the following parameter(s):
+
+- int ar[n]: an array of integers.
+
+## Return
+
+- long: the sum of all array elements
+
+## Input Format
+
+The first line of the input consists of an integer n.
+The next line contains  space-separated integers contained in the array.
+
+## Output Format
+
+Return the integer sum of the elements in the array.
+
+## Constraints
+
+$ 1 <= n < 10 $ \
+$ 0 <= ar[i] <= 10^10 $
+
+## Sample Input
+
+```text
+5
+1000000001 1000000002 1000000003 1000000004 1000000005
+```
+
+## Output
+
+```text
+5000000015
+```
+
+## Note
+
+The range of the 32-bit integer is
+($ -2^31 $) to ($ 2^31 - 1 $) or $ [-2147483648, 2147483647] $
+When we add several integer values, the resulting sum might exceed the
+above range. You might need to use long int C/C++/Java to store such sums.