Rust: Two Pointers (two_sum, 3sum))

rust/01_arrays_&_hashing/217_contains_duplicates.rs

@@ -4,15 +4,15 @@ impl Solution {
  pub fn contains_duplicate(nums: Vec<i32>) -> bool {
  let mut map = HashSet::new();
 
- for n in nums.iter(){
+ for &n in nums.iter(){
 
- if map.contains(n){
+ if map.contains(&n){
  return true; 
  }
 
  map.insert(n); 
  }; 
 
- false 
+ false
  }
-}
+}

rust/01_arrays_&_hashing/347_top_k_frequent_elements.rs

@@ -11,7 +11,7 @@ impl Solution {
 
  let mut freq: Vec<(i32, i32)> = map.into_iter().collect();
 
- let res = if k == arr.len() as i32{
+ let res = if k == freq.len() as i32{
  &freq
  }else{
  quick_select(&mut freq, k)

rust/01_arrays_&_hashing/49_group_anagrams.rs

@@ -2,10 +2,10 @@ use std::collections::HashMap;
 
 impl Solution {
  pub fn group_anagrams(strs: Vec<String>) -> Vec<Vec<String>> {
- let mut map: HashMap<[u16; 26], Vec<String>> = HashMap::new();
+ let mut map: HashMap<[u8; 26], Vec<String>> = HashMap::new();
 
  for s in strs{
- let mut key = [0_u16; 26];
+ let mut key = [0_u8; 26];
 
  for c in s.chars(){
  key[c as usize - 'a' as usize] += 1;
@@ -18,6 +18,6 @@ impl Solution {
  }
  }
 
- map.into_values().collect::<Vec<Vec<String>>>()
+ map.into_values().collect()
  }
 }

rust/02_two_pointers/11_container_with_most_water.rs

@@ -15,7 +15,7 @@ impl Solution {
  max = area;
  }
 
- if rh< lh{
+ if rh < lh{
  while r > 0 && height[r] <= rh{
  r-=1;
  }

rust/02_two_pointers/15_3sum.rs

@@ -0,0 +1,44 @@
+impl Solution {
+ pub fn three_sum(mut nums: Vec<i32>) -> Vec<Vec<i32>> {
+ nums.sort_unstable();
+
+ let mut res = vec![];
+
+ for i in 0..nums.len() - 1{
+ let n1 = nums[i];
+
+ if i > 0 && n1 == nums[i - 1]{
+ continue;
+ }
+
+ let (mut l, mut r) = (i + 1, nums.len() - 1);
+
+ while l < r{
+ let n2 = nums[l];
+ let n3 = nums[r];
+
+ let sum = n1 + n2 + n3;
+
+ if sum > 0{
+ r-=1;
+ }else if sum < 0{
+ l+=1;
+ }else{
+ res.push(vec![n1, n2, n3]);
+
+ while l < r && n2 == nums[l + 1]{
+ l+=1;
+ }
+ l+=1;
+
+ while l < r && n3 == nums[r - 1]{
+ r-=1;
+ }
+ r-=1;
+ }
+ }
+ }
+
+ res
+ }
+}

rust/02_two_pointers/167_two_sum_II.rs

@@ -0,0 +1,19 @@
+impl Solution {
+ pub fn two_sum(numbers: Vec<i32>, target: i32) -> Vec<i32> {
+ let (mut l, mut r) = (0, numbers.len() - 1);
+
+ while l < r{
+ let sum = numbers[l] + numbers[r];
+
+ if sum > target{
+ r-=1;
+ }else if sum < target{
+ l+=1;
+ }else{
+ return vec![(l + 1) as i32, (r + 1) as i32];
+ }
+ }
+
+ unreachable!()
+ }
+}