# Sudoku Solver LeetCode Programming Solutions | LeetCode Problem Solutions in C++, Java, & Python [💯Correct]

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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 Sudoku Solver 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.

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Link for the ProblemSudoku Solver– LeetCode Problem

`Sudoku Solver– LeetCode Problem`

### Problem:

Write a program to solve a Sudoku puzzle by filling the empty cells.

A sudoku solution must satisfy all of the following rules:

1. Each of the digits `1-9` must occur exactly once in each row.
2. Each of the digits `1-9` must occur exactly once in each column.
3. Each of the digits `1-9` must occur exactly once in each of the 9 `3x3` sub-boxes of the grid.

The `'.'` character indicates empty cells.

Example 1:

```Input: board = [["5","3",".",".","7",".",".",".","."],["6",".",".","1","9","5",".",".","."],[".","9","8",".",".",".",".","6","."],["8",".",".",".","6",".",".",".","3"],["4",".",".","8",".","3",".",".","1"],["7",".",".",".","2",".",".",".","6"],[".","6",".",".",".",".","2","8","."],[".",".",".","4","1","9",".",".","5"],[".",".",".",".","8",".",".","7","9"]]
Output: [["5","3","4","6","7","8","9","1","2"],["6","7","2","1","9","5","3","4","8"],["1","9","8","3","4","2","5","6","7"],["8","5","9","7","6","1","4","2","3"],["4","2","6","8","5","3","7","9","1"],["7","1","3","9","2","4","8","5","6"],["9","6","1","5","3","7","2","8","4"],["2","8","7","4","1","9","6","3","5"],["3","4","5","2","8","6","1","7","9"]]
Explanation: The input board is shown above and the only valid solution is shown below:  ```

Constraints:

• `board.length == 9`
• `board[i].length == 9`
• `board[i][j]` is a digit or `'.'`.
• It is guaranteed that the input board has only one solution.
`Sudoku Solver– LeetCode Solutions`
```class Solution {
public:
void solveSudoku(vector<vector<char>>& board) {
solve(board, 0);
}

private:
bool solve(vector<vector<char>>& board, int s) {
if (s == 81)
return true;

const int i = s / 9;
const int j = s % 9;

if (board[i][j] != '.')
return solve(board, s + 1);

for (char c = '1'; c <= '9'; ++c)
if (isValid(board, i, j, c)) {
board[i][j] = c;
if (solve(board, s + 1))
return true;
board[i][j] = '.';
}

return false;
}

bool isValid(vector<vector<char>>& board, int row, int col, char c) {
for (int i = 0; i < 9; ++i)
if (board[i][col] == c || board[row][i] == c ||
board[3 * (row / 3) + i / 3][3 * (col / 3) + i % 3] == c)
return false;
return true;
}
};```
```class Solution {
public void solveSudoku(char[][] board) {
dfs(board, 0);
}

private boolean dfs(char[][] board, int s) {
if (s == 81)
return true;

final int i = s / 9;
final int j = s % 9;

if (board[i][j] != '.')
return dfs(board, s + 1);

for (char c = '1'; c <= '9'; ++c)
if (isValid(board, i, j, c)) {
board[i][j] = c;
if (dfs(board, s + 1))
return true;
board[i][j] = '.';
}

return false;
}

private boolean isValid(char[][] board, int row, int col, char c) {
for (int i = 0; i < 9; ++i)
if (board[i][col] == c || board[row][i] == c ||
board[3 * (row / 3) + i / 3][3 * (col / 3) + i % 3] == c)
return false;
return true;
}
}```
```class Solution:
def solveSudoku(self, board: List[List[str]]) -> None:
def isValid(row: int, col: int, c: chr) -> bool:
for i in range(9):
if board[i][col] == c or \
board[row][i] == c or \
board[3 * (row // 3) + i // 3][3 * (col // 3) + i % 3] == c:
return False
return True

def solve(s: int) -> bool:
if s == 81:
return True

i = s // 9
j = s % 9

if board[i][j] != '.':
return solve(s + 1)

for c in string.digits[1:]:
if isValid(i, j, c):
board[i][j] = c
if solve(s + 1):
return True
board[i][j] = '.'

return False

solve(0)``` 