Create SumOfOddNumbers.java

Author: cbarkinozer

StreamSolutions/SumOfOddNumbers.java

@@ -0,0 +1,26 @@
+/*
+Given the triangle of consecutive odd numbers:
+
+             1
+          3     5
+       7     9    11
+   13    15    17    19
+21    23    25    27    29
+...
+Calculate the sum of the numbers in the nth row of this triangle (starting at index 1) e.g.: (Input --> Output)
+
+1 -->  1
+2 --> 3 + 5 = 8
+*/
+
+import java.util.stream.IntStream;
+
+class RowSumOddNumbers {
+    public static long rowSumOddNumbers(int rowNumber) {
+        int startingNumber = (rowNumber - 1) * rowNumber + 1;
+        return IntStream.range(startingNumber, startingNumber + rowNumber * 2)
+                .filter(number -> number % 2 != 0)
+                .sum();
+    }
+
+}