rs: add «349. Intersection of Two Arrays»

Signed-off-by: Matej Focko <mfocko@redhat.com>

rs/intersection-of-two-arrays.rs

@@ -0,0 +1,17 @@
+use std::collections::HashSet;
+
+impl Solution {
+    pub fn intersection(mut nums1: Vec<i32>, mut nums2: Vec<i32>) -> Vec<i32> {
+        // if ‹nums1› is bigger, swap them
+        if nums1.len() > nums2.len() {
+            return Self::intersection(nums2, nums1);
+        }
+
+        let nums: HashSet<i32> = nums1.into_iter().collect();
+        nums2.sort_unstable();
+
+        nums.into_iter()
+            .filter(|x| nums2.binary_search(x).is_ok())
+            .collect()
+    }
+}