Merge pull request #2348 from DaleStudy/week1

[DaleSeo] WEEK 1 Solutions

Author: DaleSeo

two-sum/DaleSeo.rs

@@ -0,0 +1,17 @@
+use std::collections::HashMap;
+
+// TC: O(n)
+// SC: O(n)
+impl Solution {
+    pub fn two_sum(nums: Vec<i32>, target: i32) -> Vec<i32> {
+        let mut indices = HashMap::new();
+        for (i, &num) in nums.iter().enumerate() {
+            let complement = target - num;
+            if let Some(&j) = indices.get(&complement) {
+                return vec![j as i32, i as i32];
+            }
+            indices.insert(num, i);
+        }
+        vec![]
+    }
+}