improve on repeated groups implementation

repeated-groups/src/main.rs

@@ -16,32 +16,20 @@ fn main() {
 
 fn repeated_groups(nums: Vec<isize>) -> Vec<Vec<isize>> {
     let mut i = 0;
-    let mut j = 0;
+    let mut j = i + 1;
 
     let mut res: Vec<Vec<isize>> = vec![];
-    let mut curr: Vec<isize> = vec![];
-
     while j < nums.len() {
-        if nums[i] != nums[j] {
-            if curr.len() > 1 {
-                res.push(curr);
-            }
-
-            i = j;
+        while j < nums.len() && nums[i] == nums[j] {
             j += 1;
-            curr = vec![nums[i]];
-            continue;
         }
 
-        curr.push(nums[i]);
-        j += 1;
+        if j - i > 1 {
+            res.push(nums[i..j].to_vec());
         }
 
-    // If the last iteration is a repeated group, the loop exits before appending
-    // the last group to the results, so we check here for what the last group was
-    // and add it to the result if need be.
-    if curr.len() > 1 {
-        res.push(curr);
+        i = j;
+        j += 1;
     }
 
     res