solves #2894: Divisible and Non-divisible Sums Difference in java

Author: anishLearnsToCode

README.md

@@ -859,7 +859,7 @@
 | 2864 | [Maximum Odd Binary Number](https://leetcode.com/problems/maximum-odd-binary-number)                                                                                   |                                                                                   [![Java](assets/java.png)](src/MaximumOddBinaryNumber.java)                                                                                    |                                                                                                                                   |
 | 2869 | [Minimum Operations to Collect Elements](https://leetcode.com/problems/minimum-operations-to-collect-elements)                                                         |                                                                             [![Java](assets/java.png)](src/MinimumOperationsToCollectElements.java)                                                                              |                                                                                                                                   |
 | 2873 | [Maximum Value of an Ordered Triplet I](https://leetcode.com/problems/maximum-value-of-an-ordered-triplet-i)                                                           |                                                                               [![Java](assets/java.png)](src/MaximumValueOfAnOrderedTripletI.java)                                                                               |                                                                                                                                   |
-| 2894 | [Divisible and Non-divisible Sums Difference](https://leetcode.com/problems/divisible-and-non-divisible-sums-difference)                                               |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2894 | [Divisible and Non-divisible Sums Difference](https://leetcode.com/problems/divisible-and-non-divisible-sums-difference)                                               |                                                                           [![Java](assets/java.png)](src/DivisibleAndNonDivisibleSumsDifference.java)                                                                            |                                                                                                                                   |
 | 2899 | [Last Visited Integers](https://leetcode.com/problems/last-visited-integers)                                                                                           |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2900 | [Longest Unequal Adjacent Groups Subsequence I](https://leetcode.com/problems/longest-unequal-adjacent-groups-subsequence-i)                                           |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2903 | [Find Indices With Index and Value Difference I](https://leetcode.com/problems/find-indices-with-index-and-value-difference-i)                                         |                                                                                                                                                                                                                                  |                                                                                                                                   |

src/DivisibleAndNonDivisibleSumsDifference.java

@@ -0,0 +1,22 @@
+// https://leetcode.com/problems/divisible-and-non-divisible-sums-difference
+// T: O(N)
+// S: O(1)
+
+public class DivisibleAndNonDivisibleSumsDifference {
+    public int differenceOfSums(int n, int m) {
+        final int sumDivisibleIntegers = getSumOfDivisibleIntegers(n, m);
+        final int sumNonDivisibleIntegers = (n * (n + 1)) / 2 - sumDivisibleIntegers;
+
+        return sumNonDivisibleIntegers - sumDivisibleIntegers;
+    }
+
+    private static int getSumOfDivisibleIntegers(int n, int m) {
+        int sum = 0;
+        for (int i = 1 ; i <= n ; i++) {
+            if (i % m == 0) {
+                sum += i;
+            }
+        }
+        return sum;
+    }
+ }