20250122 finished.

src/problem/mod.rs

@@ -446,3 +446,5 @@ mod p2266_count_number_of_texts;
 mod p2239_find_closest_number_to_zero;
 
 mod p2218_maximum_value_of_k_coins_from_piles;
+
+mod p1561_maximum_number_of_coins_you_can_get;

src/problem/p1561_maximum_number_of_coins_you_can_get.rs

@@ -0,0 +1,35 @@
+/**
+ * [1561] Maximum Number of Coins You Can Get
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn max_coins(mut piles: Vec<i32>) -> i32 {
+        let n = piles.len() / 3;
+        piles.sort_unstable_by(|a, b| b.cmp(a));
+
+        let mut result = 0;
+
+        for i in (0..n).map(|x| x * 2 + 1) {
+            result += piles[i]
+        }
+
+        result
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1561() {
+        assert_eq!(9, Solution::max_coins(vec![2, 4, 1, 2, 7, 8]));
+        assert_eq!(4, Solution::max_coins(vec![2, 4, 5]));
+        assert_eq!(18, Solution::max_coins(vec![9, 8, 7, 6, 5, 1, 2, 3, 4]));
+    }
+}