20250527 finished.

src/problem/mod.rs

@@ -678,3 +678,5 @@ mod p2942_find_words_containing_character;
 mod p2131_longest_palindrome_by_concatenating_two_letter_words;
 
 mod p1857_largest_color_value_in_a_directed_graph;
+
+mod p2894_divisible_and_non_divisible_sums_difference;

src/problem/p2894_divisible_and_non_divisible_sums_difference.rs

@@ -0,0 +1,31 @@
+/**
+ * [2894] Divisible and Non-divisible Sums Difference
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn difference_of_sums(n: i32, m: i32) -> i32 {
+        (1..=n)
+            .filter_map(|x| if x % m != 0 { Some(x) } else { None })
+            .sum::<i32>()
+            - (1..=n)
+                .filter_map(|x| if x % m == 0 { Some(x) } else { None })
+                .sum::<i32>()
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_2894() {
+        assert_eq!(19, Solution::difference_of_sums(10, 3));
+        assert_eq!(15, Solution::difference_of_sums(5, 6));
+        assert_eq!(-15, Solution::difference_of_sums(5, 1));
+    }
+}