20241215 finished.

src/problem/mod.rs

@@ -370,3 +370,5 @@ mod p2931_maximum_spending_after_buying_items;
 mod p3264_final_array_state_after_k_multiplication_operations_i;
 
 mod p3266_final_array_state_after_k_multiplication_operations_ii;
+
+mod p1338_reduce_array_size_to_the_half;

src/problem/p1338_reduce_array_size_to_the_half.rs

@@ -0,0 +1,54 @@
+/**
+ * [1338] Reduce Array Size to The Half
+ */
+pub struct Solution {}
+
+// submission codes start here
+use std::collections::BinaryHeap;
+use std::collections::HashMap;
+
+impl Solution {
+    pub fn min_set_size(arr: Vec<i32>) -> i32 {
+        let mut map = HashMap::new();
+
+        for &i in arr.iter() {
+            let entry = map.entry(i).or_insert(0);
+            *entry += 1;
+        }
+
+        let mut heap = BinaryHeap::with_capacity(map.len());
+
+        for (_, v) in map {
+            heap.push(v);
+        }
+
+        let mut result = 0;
+        let mut count = arr.len();
+        let target = count / 2;
+
+        while count > target {
+            if let Some(head) = heap.pop() {
+                count -= head;
+                result += 1;
+            }
+        }
+
+        result
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1338() {
+        assert_eq!(
+            2,
+            Solution::min_set_size(vec![3, 3, 3, 3, 5, 5, 5, 2, 2, 7])
+        );
+        assert_eq!(1, Solution::min_set_size(vec![7, 7, 7, 7, 7, 7]));
+    }
+}