4Sum LeetCode Programming Solutions | LeetCode Problem Solutions in C++, Java, & Python [💯Correct]

4Sum LeetCode Problem | LeetCode Problems For Beginners | LeetCode Problems & Solutions | Improve Problem Solving Skills | LeetCode Problems Java | LeetCode Problems C++

Hello Programmers/Coders, Today we are going to share solutions to the Programming problems of LeetCode Solutions in C++, Java, & Python. At Each Problem with Successful submission with all Test Cases Passed, you will get a score or marks and LeetCode Coins. And after solving maximum problems, you will be getting stars. This will highlight your profile to the recruiters.

In this post, you will find the solution for the 4Sum in C++, Java & Python-LeetCode problem. We are providing the correct and tested solutions to coding problems present on LeetCode. If you are not able to solve any problem, then you can take help from our Blog/website.

Use “Ctrl+F” To Find Any Questions Answer. & For Mobile User, You Just Need To Click On Three dots In Your Browser & You Will Get A “Find” Option There. Use These Option to Get Any Random Questions Answer.

About LeetCode

LeetCode is one of the most well-known online judge platforms to help you enhance your skills, expand your knowledge and prepare for technical interviews. 

LeetCode is for software engineers who are looking to practice technical questions and advance their skills. Mastering the questions in each level on LeetCode is a good way to prepare for technical interviews and keep your skills sharp. They also have a repository of solutions with the reasoning behind each step.

LeetCode has over 1,900 questions for you to practice, covering many different programming concepts. Every coding problem has a classification of either EasyMedium, or Hard.

LeetCode problems focus on algorithms and data structures. Here is some topic you can find problems on LeetCode:

  • Mathematics/Basic Logical Based Questions
  • Arrays
  • Strings
  • Hash Table
  • Dynamic Programming
  • Stack & Queue
  • Trees & Graphs
  • Greedy Algorithms
  • Breadth-First Search
  • Depth-First Search
  • Sorting & Searching
  • BST (Binary Search Tree)
  • Database
  • Linked List
  • Recursion, etc.

Leetcode has a huge number of test cases and questions from interviews too like Google, Amazon, Microsoft, Facebook, Adobe, Oracle, Linkedin, Goldman Sachs, etc. LeetCode helps you in getting a job in Top MNCs. To crack FAANG Companies, LeetCode problems can help you in building your logic.

Link for the Problem4Sum– LeetCode Problem

4Sum– LeetCode Problem

Problem:

Given an array nums of n integers, return an array of all the unique quadruplets [nums[a], nums[b], nums[c], nums[d]] such that:

  • 0 <= a, b, c, d < n
  • abc, and d are distinct.
  • nums[a] + nums[b] + nums[c] + nums[d] == target

You may return the answer in any order.

Example 1:

Input: nums = [1,0,-1,0,-2,2], target = 0
Output: [[-2,-1,1,2],[-2,0,0,2],[-1,0,0,1]]

Example 2:

Input: nums = [2,2,2,2,2], target = 8
Output: [[2,2,2,2]]

Constraints:

  • 1 <= nums.length <= 200
  • -109 <= nums[i] <= 109
  • -109 <= target <= 109
4Sum– LeetCode Solutions
class Solution {
 public:
  vector<vector<int>> fourSum(vector<int>& nums, int target) {
    vector<vector<int>> ans;
    vector<int> path;

    sort(begin(nums), end(nums));
    nSum(nums, 4, target, 0, nums.size() - 1, path, ans);

    return ans;
  }

 private:
  // in [l, r], find n numbers add up to the target
  void nSum(const vector<int>& nums, int n, int target, int l, int r,
            vector<int>& path, vector<vector<int>>& ans) {
    if (r - l + 1 < n || target < nums[l] * n || target > nums[r] * n)
      return;
    if (n == 2) {
      // very similar to the sub procedure in 15. 3Sum
      while (l < r) {
        const int sum = nums[l] + nums[r];
        if (sum == target) {
          path.push_back(nums[l]);
          path.push_back(nums[r]);
          ans.push_back(path);
          path.pop_back();
          path.pop_back();
          ++l;
          --r;
          while (l < r && nums[l] == nums[l - 1])
            ++l;
          while (l < r && nums[r] == nums[r + 1])
            --r;
        } else if (sum < target) {
          ++l;
        } else {
          --r;
        }
      }
      return;
    }

    for (int i = l; i <= r; ++i) {
      if (i > l && nums[i] == nums[i - 1])
        continue;
      path.push_back(nums[i]);
      nSum(nums, n - 1, target - nums[i], i + 1, r, path, ans);
      path.pop_back();
    }
  }
};
class Solution {
  public List<List<Integer>> fourSum(int[] nums, int target) {
    List<List<Integer>> ans = new ArrayList<>();

    Arrays.sort(nums);
    nSum(nums, 4, target, 0, nums.length - 1, new ArrayList<>(), ans);

    return ans;
  }

  // in [l, r], find n numbers add up to the target
  private void nSum(int[] nums, int n, int target, int l, int r, List<Integer> path,
                    List<List<Integer>> ans) {
    if (r - l + 1 < n || target < nums[l] * n || target > nums[r] * n)
      return;
    if (n == 2) {
      // very similar to the sub procedure in 15. 3Sum
      while (l < r) {
        final int sum = nums[l] + nums[r];
        if (sum == target) {
          path.add(nums[l]);
          path.add(nums[r]);
          ans.add(new ArrayList<>(path));
          path.remove(path.size() - 1);
          path.remove(path.size() - 1);
          ++l;
          --r;
          while (l < r && nums[l] == nums[l - 1])
            ++l;
          while (l < r && nums[r] == nums[r + 1])
            --r;
        } else if (sum < target) {
          ++l;
        } else {
          --r;
        }
      }
      return;
    }

    for (int i = l; i <= r; ++i) {
      if (i > l && nums[i] == nums[i - 1])
        continue;
      path.add(nums[i]);
      nSum(nums, n - 1, target - nums[i], i + 1, r, path, ans);
      path.remove(path.size() - 1);
    }
  }
}
class Solution:
  def fourSum(self, nums: List[int], target: int):
    def nSum(l: int, r: int, target: int, n: int, path: List[int], ans: List[List[int]]) -> None:
      if r - l + 1 < n or n < 2 or target < nums[l] * n or target > nums[r] * n:
        return
      if n == 2:
        while l < r:
          sum = nums[l] + nums[r]
          if sum == target:
            ans.append(path + [nums[l], nums[r]])
            l += 1
            while nums[l] == nums[l - 1] and l < r:
              l += 1
          elif sum < target:
            l += 1
          else:
            r -= 1
        return

      for i in range(l, r + 1):
        if i > l and nums[i] == nums[i - 1]:
          continue

        nSum(i + 1, r, target - nums[i], n - 1, path + [nums[i]], ans)

    ans = []

    nums.sort()
    nSum(0, len(nums) - 1, target, 4, [], ans)

    return ans

687 thoughts on “4Sum LeetCode Programming Solutions | LeetCode Problem Solutions in C++, Java, & Python [💯Correct]”

  1. Fans of DC comics need no introduction to the Star Sapphire. However, for those who are not keen followers of the DC comics, Star Sapphire is the name of the female warrior who guards the Queen. Some people insist that online slot machines are based on chance and believe that their fate lies in the hands of the random number generator (RNG). However, there are many players that prefer to play according to a particular pre-determined system or method. There are different pattern strategies that have been created for use at slot machine games at the best online casinos and the three star slots strategy is one of them. Explore the sandy wasteland of the wild west in Greentube’s Lone Star Jackpots. This megaways style slot machine has all of its paylines active, allowing players to win in over 200 ways.
    https://mike-wiki.win/index.php?title=Online_casino_paysafecard_bonus_pogo
    Check: If no other poker player has bet yet and it is your turn, you can decline to bet as well, passing it along to the next person or poker round. This is called a “check”. That’s where you find the best free online poker games with fake money to play with other poker players from all over the world and engage in exciting Texas Holdem Poker and Omaha ring games and tournaments. To know what operators offer legal online poker games in these states, check our pages dedicated to PA Poker Sites and NJ Poker Sites. Also, you can follow the legislative process and know when more states are likely to regulate online poker via our US Poker Map. In addition to free poker games, we offer you the chance to win free money with the many freerolls that run every day. Enter these free poker tournaments and you’ll have the chance to come away with real money in your account – and it’s all on the house. To find freerolls, head to the ‘Tournaments tab’ (desktop), or ‘Tourney’ tab accessed via the Lobby (mobile), and select ‘Freeroll’ from the ‘Buy-in’ filter.

    Reply
  2. Het was Fatima’s eigen idee om eens mee te doen aan pokertoernooien omdat ze er al langer naar benieuwd was. Vanwege de onterechte slechte naam van pokeren, deed ze haar omgeving versteld staan. Haar ouders waren daar zeker niet blij mee, omdat de pokerwereld bekendstond als een spel waaraan vooral criminelen meededen. Maar Moreira de Melo heeft laten zien dat de pokerwereld flink geprofessionaliseerd is en heeft ook zeker bijgedragen aan het verbeteren van de naam rondom het casinospel. In de tien jaar als pokerspeelster heeft Fatima zeen dikke 577.000 dollar verdiend. Ga je beginnen met poker spelen of ben je van plan om je spel te verbeteren? Wij helpen je om in korte tijd een goede pokerspeler te worden, je krijgt belangrijke aanwijzingen en handige pokertips om je spel naar een hoger level te brengen.
    http://www.srim.co.kr/bbs/board.php?bo_table=free&wr_id=79266
    Het is belangrijk om op te merken dat er meestal geen extra kosten verbonden zijn aan het gebruik van iDEAL. Het is echter altijd een goed idee om het kostenbeleid van zowel de huisbank als het online casino te controleren om er zeker van te zijn dat er geen verborgen kosten zijn. “Fijn dat ik gewoon geld over kan maken met iDeal en dat het bovendien meteen beschikbaar is om mee te gaan spelen,” vertelde ons een van onze spelers. Een andere vult aan: “iDeal werkt ontzettend eenvoudig. Goed om te zien dat het gaat om een veilige verbinding. Nu ik in het online casino met iDeal kan betalen gok ik voortaan gewoon vanuit huis.” Al met al draagt het gebruik van iDEAL als verplichte betaalmethode bij vergunninghoudende online gokbedrijven in Nederland bij aan het veiliger en betrouwbaarder maken van online gokken. Het vertrouwen van spelers in de branche wordt landelijk versterkt.

    Reply
  3. cost of cheap mobic without a prescription [url=https://mobic.store/#]how to get generic mobic without a prescription[/url] where can i buy generic mobic

    Reply
  4. best canadian online pharmacy [url=http://certifiedcanadapills.pro/#]canadian pharmacy prices[/url] online canadian pharmacy review

    Reply
  5. Contrary to most other VIP programs, Greenplay Casino aims to reward all of their active members. The loyalty scheme has seven levels. The more active you are at the casino and the more you bet, the higher your level will be. The higher your VIP level, the better your advantages will be, for example exclusive bonuses, quicker withdrawals, access to live tournaments, cashback offers, etc. The highest level is referred to as the “Prestige VIP” level and rewards players with high cash out limits, lots of monthly cashback, and 50 free games every Sunday. Contrary to most other VIP programs, Greenplay Casino aims to reward all of their active members. The loyalty scheme has seven levels. The more active you are at the casino and the more you bet, the higher your level will be. The higher your VIP level, the better your advantages will be, for example exclusive bonuses, quicker withdrawals, access to live tournaments, cashback offers, etc. The highest level is referred to as the “Prestige VIP” level and rewards players with high cash out limits, lots of monthly cashback, and 50 free games every Sunday.
    http://www.naturesoop.co.kr/bbs/board.php?bo_table=free&wr_id=12882
    Secure Your Spot You don’t need to do your gaming in the casino to win big. On MedallionClass® ships with Ocean® Casino, you can wager real money on slots, poker, bingo, roulette and more. * Dye sublimation printing professional roulette layout; Now you know why ICE Casino is the best online casino you can find: we offer over 3,500 games and make sure players of all kinds have options to keep them entertained for a long time. Our welcome bonus of 1,500 USD EUR + 270 FS gives our new members a quick start. After you become a member, you can continue to earn reload and cashback bonuses. With our 24 7 available casino online customer support, we both solve your problems immediately and ensure that our communication with you is never interrupted. If you are looking for a safe, legal, and fair casino virtual experience, you are in the right place: create an account right now, make your first deposit, and start playing your favourite games with an incredible bonus!

    Reply
  6. 98+ currencies available to transfer to 130+ countries BTC to AUD The USD price of Bitcoin today (as of April 11, 2021) is $59,822.90 for one coin. You can convert 0.005 BTC to 151.12 USD. Live BTC to USD calculator is based on live data from multiple crypto exchanges. Last price update for BTC to USD converter was today at 09:30 UTC. 5.0E-5 BTC = 1.51 USD Disclaimer: Buy Bitcoin Worldwide is not offering, promoting, or encouraging the purchase, sale, or trade of any security or commodity. Buy Bitcoin Worldwide is for educational purposes only. Every visitor to Buy Bitcoin Worldwide should consult a professional financial advisor before engaging in such practices. Buy Bitcoin Worldwide, nor any of its owners, employees or agents, are licensed broker-dealers, investment advisers, or hold any relevant distinction or title with respect to investing. Buy Bitcoin Worldwide does not promote, facilitate or engage in futures, options contracts or any other form of derivatives trading.
    http://xn--2i0b75tq8gu5o.com/bbs/board.php?bo_table=free&wr_id=31697
    “Trading of Bitcoin on Coinbase represents a significant portion of US-based Bitcoin trading,” the exchange said in the filing. “According to the Sponsor, the Exchange aims to enter into a surveillance-sharing agreement with Coinbase, the operator of the largest United States-based spot trading platform for Bitcoin representing a majority of global spot BTC trading paired with USD.” Valkyrie updated its filing after the U.S. Securities and Exchange Commission (SEC) rejected its previous attempts for failing to meet regulatory requirements for preventing fraudulent acts and protecting investors. Create a list of the investments you want to track. The Valkyrie ETF approval was only a matter of time since ProShares Strategy Bitcoin ETF was given the green light to debut on a US exchange. Besides Valkyrie, another independent investment management company in Invesco was also close to getting their ETF approval to feature among the first funds to be traded in the US.

    Reply
  7. Anna Berezina is a honoured inventor and demagogue in the area of psychology. With a background in clinical luny and extensive study sagacity, Anna has dedicated her calling to armistice lenient behavior and mental health: http://mlmoli.net/space-uid-755773.html. By virtue of her work, she has made significant contributions to the battleground and has behove a respected reflection leader.

    Anna’s mastery spans several areas of feelings, including cognitive disturbed, unmistakable looney, and zealous intelligence. Her voluminous facts in these domains allows her to stock up valuable insights and strategies in return individuals seeking offensive growth and well-being.

    As an initiator, Anna has written distinct controlling books that have garnered widespread perception and praise. Her books provide functional par‘nesis and evidence-based approaches to remedy individuals command fulfilling lives and develop resilient mindsets. Via combining her clinical dexterity with her passion quest of portion others, Anna’s writings have resonated with readers all the world.

    Reply
  8. Anna Berezina is a highly talented and famend artist, recognized for her distinctive and captivating artworks that never fail to go away a long-lasting impression. Her paintings beautifully showcase mesmerizing landscapes and vibrant nature scenes, transporting viewers to enchanting worlds crammed with awe and marvel.

    What units [url=https://w1000w.com/wp-content/pages/anna-berezina_123.html]Berezina[/url] apart is her distinctive consideration to element and her remarkable mastery of colour. Each stroke of her brush is deliberate and purposeful, creating depth and dimension that convey her work to life. Her meticulous approach to capturing the essence of her topics permits her to create really breathtaking artworks.

    Anna finds inspiration in her travels and the magnificence of the pure world. She has a deep appreciation for the awe-inspiring landscapes she encounters, and this is evident in her work. Whether it’s a serene seashore at sunset, an impressive mountain range, or a peaceable forest full of vibrant foliage, Anna has a outstanding capacity to capture the essence and spirit of those locations.

    With a singular creative type that combines elements of realism and impressionism, Anna’s work is a visual feast for the eyes. Her paintings are a harmonious blend of precise particulars and gentle, dreamlike brushstrokes. This fusion creates a captivating visual experience that transports viewers right into a world of tranquility and wonder.

    Anna’s expertise and inventive vision have earned her recognition and acclaim within the art world. Her work has been exhibited in prestigious galleries across the globe, attracting the attention of artwork fanatics and collectors alike. Each of her pieces has a way of resonating with viewers on a deeply private level, evoking feelings and sparking a way of connection with the natural world.

    As Anna continues to create gorgeous artworks, she leaves an indelible mark on the world of art. Her capability to capture the wonder and essence of nature is truly outstanding, and her work function a testomony to her creative prowess and unwavering ardour for her craft. Anna Berezina is an artist whose work will proceed to captivate and inspire for years to return..

    Reply
  9. Αν γίνει επιτυχία, το Taj πιθανότατα να βλάψει τα άλλα δύο καζίνο του Atlantic City που είναι πολύ σημαντικά για το οικονομικό στάτους του Trump. Κατά τη διάρκεια των πρώτων τριών εβδομάδων των εργασιών του Taj, τα κέρδη στο Trump Plaza μειώθηκαν κατά 12,3% και κατά 1,7% στο Castle Trump. Υπάρχει ένας ενθουσιασμός στην ομάδα των Nintenders με το HADES της Supergiant Games, ο οποίος έχει κατακλύσει και τα μέλη μας. Είναι ένας τίτλος βασισμένος στην Ελληνική μυθολογία και έχει λάβει εκπληκτικά σκορ στα Reviews.
    https://finnserb112322.nizarblog.com/21421129/πωσ-παιζεται-το-μπλακ-τζακ
    Tagged with: ΕΛΛΗΝΕΣ ΕΠΑΙΞΑΝ ΚΑΖΙΝΟ ΣΚΟΠΙΑ ΧΙΛΙΑΔΕΣ To καζίνο Flamingo είναι το δεύτερο καζίνο που βρίσκεται στα Σκόπια στην Γεύγελη, κοντά στα σύνορα με την Ελλάδα. Δεν θέλει ρώτημα ότι οι περισσότεροι πελάτες του καζίνο Flamingo…περισσότερα για το καζίνο Flamingo στα Σκόπια 13 Ιουλίου 2023 Το πρώτο μεγάλο τουρνουά στην Ελλάδα Ellinika Kazino © Eλληνικά Καζίνο – Σκοπιανά Καζίνο elpizw me oli auti tin dimosiotita na xypnisoun oloi oi sumpatriowtes mas pou pane kai ta skane stous skopianous….

    Reply
  10. Pingback: whatismyip
  11. Hiya! Quick question that’s entirely off topic. Do you know how to make
    your site mobile friendly? My weblog looks weird when browsing
    from my iphone. I’m trying to find a theme or plugin that might be able to resolve this issue.

    If you have any suggestions, please share. With thanks!

    Reply
  12. Buy Cialis online [url=https://cialis.foundation/#]Generic Cialis without a doctor prescription[/url] Cialis without a doctor prescription

    Reply
  13. canadian pharmacy 24 com: drugs from canada – canada pharmacy online legit canadapharmacy.guru
    india pharmacy [url=http://indiapharmacy.pro/#]mail order pharmacy india[/url] indian pharmacies safe indiapharmacy.pro

    Reply
  14. zithromax cost uk [url=http://azithromycin.bar/#]zithromax without prescription[/url] buy zithromax without prescription online

    Reply
  15. We welcome your creative board game ideas and will be happy to help you realize them. In doing so, we bring more than 25 years of industry experience and thus extensive know-how to the table. Your satisfaction is our claim, we achieve this through high quality standards and great commitment. Online Ludo is a well-liked online version  of the traditional board game. The basic rules of the game remain the same, but specific crucial guidelines are unique to online Ludo that players should be aware of: How does a studio translate a nostalgic Indian strategy board game to a mobile gaming app and reach a vast range of gamers? A simple concept with a short learning curve brought many nongamers into the realm of the Ludo King mobile app. SHIPPING OR LOCAL DELIVERY AVAILABLE
    https://rylanskar024680.designertoblog.com/54147492/play-ac-baseball
    You can email the site owner to let them know you were blocked. Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page. TV More PS4 Racing Games Few futuristic racing games have reached the thrill-a-minute heights of the WipEout series, and Omega Collection truly fired the critically acclaimed PlayStation mainstay into a shiny new age. Bringing back 26 reversible tracks, 46 unique ships, and nine game modes from WipEout HD, WipEout Fury, and WipEout 2048, this PS4 remaster offers a face-melting sensation of speed with 60 frames per second visuals and a PlayStation VR mode to put you directly in the cockpit of a top of the range anti-gravity machine. Ever since the dawn of video games, challenges that feature cars have been the most popular by far! With so many enthusiasts of all ages, it’s no wonder that they still retain their popularity. After all, not everyone can afford a car, but a computer is much more accessible. Besides, boys are not the only car enthusiasts. Nowadays, this category is so varied that anybody can enjoy the drive of their dreams!

    Reply
  16. Pharmacie en ligne livraison rapide [url=https://pharmacieenligne.guru/#]Medicaments en ligne livres en 24h[/url] acheter mГ©dicaments Г  l’Г©tranger

    Reply
  17. Pharmacie en ligne pas cher [url=http://levitrafr.life/#]Levitra 20mg prix en pharmacie[/url] acheter medicament a l etranger sans ordonnance

    Reply