20250224 finished.

src/problem/mod.rs

@@ -502,3 +502,5 @@ mod p2209_minimum_white_tiles_after_covering_with_carpets;
 mod p2506_count_pairs_of_similar_strings;
 
 mod p1206_design_skiplist;
+
+mod p1656_design_an_ordered_stream;

src/problem/p1656_design_an_ordered_stream.rs

@@ -0,0 +1,71 @@
+/**
+ * [1656] Design an Ordered Stream
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+struct OrderedStream {
+    array: Vec<Option<String>>,
+    pointer: usize,
+}
+
+/**
+ * `&self` means the method takes an immutable reference.
+ * If you need a mutable reference, change it to `&mut self` instead.
+ */
+impl OrderedStream {
+    fn new(n: i32) -> Self {
+        let n = n as usize;
+
+        Self {
+            array: vec![None; n],
+            pointer: 1,
+        }
+    }
+
+    fn insert(&mut self, id_key: i32, value: String) -> Vec<String> {
+        let id = id_key as usize - 1;
+
+        self.array[id] = Some(value);
+
+        let mut result = vec![];
+        let mut pointer = self.pointer;
+
+        while pointer <= self.array.len() {
+            if let Some(item) = &self.array[pointer - 1] {
+                result.push(item.clone());
+                pointer += 1;
+            } else {
+                break;
+            }
+        }
+        self.pointer = pointer;
+
+        result
+    }
+}
+
+/**
+ * Your OrderedStream object will be instantiated and called as such:
+ * let obj = OrderedStream::new(n);
+ * let ret_1: Vec<String> = obj.insert(idKey, value);
+ */
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1656() {
+        let mut stream = OrderedStream::new(5);
+
+        assert_eq!(Vec::<&str>::new(), stream.insert(3, "ccccc".to_owned()));
+        assert_eq!(vec!["aaaaa"], stream.insert(1, "aaaaa".to_owned()));
+        assert_eq!(vec!["bbbbb", "ccccc"], stream.insert(2, "bbbbb".to_owned()));
+        assert_eq!(Vec::<&str>::new(), stream.insert(5, "eeeee".to_owned()));
+        assert_eq!(vec!["ddddd", "eeeee"], stream.insert(4, "ddddd".to_owned()));
+    }
+}