**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 **N-Queens** **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 *Easy*, *Medium*, 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 Problem** – N-Queens– LeetCode Problem

N-Queens– LeetCode Problem

**Problem:**

The **n-queens** puzzle is the problem of placing `n`

queens on an `n x n`

chessboard such that no two queens attack each other.

Given an integer `n`

, return *all distinct solutions to the n-queens puzzle*. You may return the answer in

**any order**.

Each solution contains a distinct board configuration of the n-queens’ placement, where `'Q'`

and `'.'`

both indicate a queen and an empty space, respectively.

**Example 1:**

Input:n = 4Output:[[".Q..","...Q","Q...","..Q."],["..Q.","Q...","...Q",".Q.."]]Explanation:There exist two distinct solutions to the 4-queens puzzle as shown above

**Example 2:**

Input:n = 1Output:[["Q"]]

**Constraints:**

`1 <= n <= 9`

N-Queens– LeetCode Solutions

N-Queens in C++:

struct T { int left; // sum of the subarray w/ max sum (starting from the first num) int right; // sum of the subarray w/ max sum (ending at the the last num) int mid; // sum of the subarray w/ max sum int sum; // sum of the whole array }; class Solution { public: int maxSubArray(vector<int>& nums) { const T t = divideAndConquer(nums, 0, nums.size() - 1); return t.mid; } private: T divideAndConquer(const vector<int>& nums, int l, int r) { if (l == r) return {nums[l], nums[l], nums[l], nums[l]}; const int m = l + (r - l) / 2; const T t1 = divideAndConquer(nums, l, m); const T t2 = divideAndConquer(nums, m + 1, r); const int left = max(t1.left, t1.sum + t2.left); const int right = max(t1.right + t2.sum, t2.right); const int mid = max({t1.right + t2.left, t1.mid, t2.mid}); const int sum = t1.sum + t2.sum; return {left, right, mid, sum}; }; };

N-Queens in Java:

class Solution { public List<List<String>> solveNQueens(int n) { List<List<String>> ans = new ArrayList<>(); char[][] board = new char[n][n]; for (int i = 0; i < n; ++i) Arrays.fill(board[i], '.'); dfs(n, 0, new boolean[n], new boolean[2 * n - 1], new boolean[2 * n - 1], board, ans); return ans; } private void dfs(int n, int i, boolean[] cols, boolean[] diag1, boolean[] diag2, char[][] board, List<List<String>> ans) { if (i == n) { ans.add(construct(board)); return; } for (int j = 0; j < cols.length; ++j) { if (cols[j] || diag1[i + j] || diag2[j - i + n - 1]) continue; board[i][j] = 'Q'; cols[j] = diag1[i + j] = diag2[j - i + n - 1] = true; dfs(n, i + 1, cols, diag1, diag2, board, ans); cols[j] = diag1[i + j] = diag2[j - i + n - 1] = false; board[i][j] = '.'; } } private List<String> construct(char[][] board) { List<String> listBoard = new ArrayList<>(); for (int i = 0; i < board.length; ++i) listBoard.add(String.valueOf(board[i])); return listBoard; } }

N-Queens in Python:

class Solution: def solveNQueens(self, n: int) -> List[List[str]]: ans = [] cols = [False] * n diag1 = [False] * (2 * n - 1) diag2 = [False] * (2 * n - 1) def dfs(i: int, board: List[int]) -> None: if i == n: ans.append(board) return for j in range(n): if cols[j] or diag1[i + j] or diag2[j - i + n - 1]: continue cols[j] = diag1[i + j] = diag2[j - i + n - 1] = True dfs(i + 1, board + ['.' * j + 'Q' + '.' * (n - j - 1)]) cols[j] = diag1[i + j] = diag2[j - i + n - 1] = False dfs(0, []) return ans

tadalafil 10mg uk buy cialis 20mg without prescription ed pills cheap

order duricef 500mg sale cefadroxil cheap propecia 1mg tablet

buy fluconazole 100mg pill oral cipro ciprofloxacin 1000mg usa

buy generic estrace buy lamotrigine 50mg generic prazosin online buy

order flagyl pills purchase flagyl online cheap keflex where to buy

order vermox pill buy mebendazole without prescription tadalis order online

cleocin oral erythromycin 250mg generic buy sildenafil pill

order avana without prescription buy diclofenac 100mg buy cheap diclofenac

brand tamoxifen purchase ceftin for sale ceftin over the counter

order indocin 75mg sale indomethacin order purchase suprax pills

buy trimox sale cost biaxin 500mg clarithromycin 250mg price

order bimatoprost for sale methocarbamol 500mg brand trazodone 50mg ca

clonidine online buy buy catapres sale buy tiotropium bromide 9 mcg pill

suhagra 50mg drug viagra sildenafil 25mg order sildalis pills

cost leflunomide 10mg azulfidine 500 mg pills sulfasalazine 500 mg usa

isotretinoin 10mg canada buy amoxicillin 1000mg online cheap purchase azithromycin pill

cialis 5mg pills order tadalafil 20mg sale cialis for daily use

buy azipro without a prescription buy omnacortil pills for sale cheap generic gabapentin

where to buy ivermectin prednisone 10mg brand deltasone pill

buy lasix 100mg pills doxycycline 100mg canada albuterol without prescription

vardenafil for sale vardenafil cheap hydroxychloroquine 400mg canada

order levitra for sale purchase vardenafil without prescription order plaquenil 400mg without prescription

benicar online benicar pills cost divalproex 500mg

coreg 6.25mg us buy carvedilol no prescription generic aralen

acetazolamide online isosorbide order online imuran 25mg without prescription

digoxin sale order lanoxin order molnunat pill

order naproxen 250mg pill order omnicef without prescription purchase prevacid online