Oracle: Deduplicaiton of singly linked list

Signed-off-by: yourarj <[email protected]>

 Date:      Fri Dec 29 08:17:02 2023 +0530

 On branch main

 Changes to be committed:
	new file:   .idea/misc.xml
	new file:   .idea/modules.xml
	new file:   .idea/rust-ds-algo.iml
	new file:   .idea/vcs.xml
	new file:   .idea/workspace.xml
	modified:   Cargo.lock
	modified:   Cargo.toml
	modified:   leetcode-two-sum/src/main.rs
	new file:   oracle-linked-list-unique-elements/Cargo.toml
	new file:   oracle-linked-list-unique-elements/LinkedListDeDuplication.md
	new file:   oracle-linked-list-unique-elements/src/lib.rs

Cargo.toml

@@ -43,4 +43,5 @@ members = [
     "leetcode-remove-duplicates-from-sorted-array",
     "leetcode-sqrtx",
     "leetcode-find-the-index-of-the-first-occurrence-in-a-string",
+    "oracle-linked-list-unique-elements",
 ]

leetcode-two-sum/src/main.rs

@@ -10,7 +10,7 @@ pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
     let mut answer = Vec::new();
     for (index, element) in nums.into_iter().enumerate() {
         if complement_map_with_index.contains_key(&element) {
-            answer.push(*complement_map_with_index.get(&element).unwrap().deref());
+            answer.push(*complement_map_with_index.get(&element).unwrap());
             answer.push(index as i32);
             break;
         }

oracle-linked-list-unique-elements/Cargo.toml

@@ -0,0 +1,8 @@
+ [package]
+name = "oracle-linked-list-unique-elements"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

oracle-linked-list-unique-elements/LinkedListDeDuplication.md

@@ -0,0 +1,24 @@
+# Deduplication in Singly-Linked-List
+## Asked by: Oracle
+
+Remove all instances of element from singly linked list so the resulting linked list will only contain elements whose
+occurrence was exactly once.
+
+e.g.
+Example 01
+```
+Input: 1 -> 1 -> 1 -> 2 -> 3 -> 3 -> 4
+Output: 2 -> 4
+```
+
+Example 02
+```
+Input: 1 -> 1 -> 1
+Output: null
+```
+
+Example 03
+```
+Input: 1 -> 1 -> 1 -> 2 -> 3 -> 3
+Output: 2
+```

oracle-linked-list-unique-elements/src/lib.rs

@@ -0,0 +1,61 @@
+pub fn deduplicate_linked_list(list: Vec<i32>) -> Vec<i32> {
+    let mut output = vec![];
+    for index in 0..list.len() {
+        let add_current = match (
+            if index == 0 {
+                None
+            } else {
+                list.get(index - 1)
+            },
+            list[index],
+            list.get(index + 1),
+        ) {
+            (None, _, None) => true,
+            (None, current, Some(next)) => current != *next,
+            (Some(last), current, Some(next)) => *last != current && current != *next,
+            (Some(last), current, None) => *last != current,
+        };
+
+        if add_current {
+            output.push(list[index])
+        }
+    }
+    output
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::deduplicate_linked_list;
+
+    #[test]
+    fn test_deduplicate_linked_list() {
+        assert_eq!(
+            vec![2, 4],
+            deduplicate_linked_list(vec![1, 1, 1, 2, 3, 3, 4])
+        );
+    }
+
+    // test 1 -> 1 -> 1 -> 2 -> 3 -> 3 -> 4 -> 4
+    #[test]
+    fn test_deduplicate_linked_list2() {
+        assert_eq!(
+            vec![2],
+            deduplicate_linked_list(vec![1, 1, 1, 2, 3, 3, 4, 4])
+        );
+    }
+
+    #[test]
+    fn test_remove_no_elements_from_all_unique_linked_list() {
+        assert_eq!(vec![1, 2, 3, 4], deduplicate_linked_list(vec![1, 2, 3, 4]));
+    }
+
+    #[test]
+    fn test_do_nothing_on_empty_linked_list() {
+        assert!(deduplicate_linked_list(vec![]).is_empty());
+    }
+
+    #[test]
+    fn test_remove_everything_from_all_duplicated_linked_list() {
+        assert!(deduplicate_linked_list(vec![100, 100]).is_empty());
+    }
+}