Merge pull request #503 from tandrimasingha/main

 Sudoku-Solver

Author: gantavyamalviya

Sudoku-Solver.cpp

@@ -0,0 +1,33 @@
+class Solution {
+public:
+    void solveSudoku(vector<vector<char>>& board) {
+        solve(board);
+    }
+    
+    bool solve(vector<vector<char>>& board){
+        for(int i=0; i<board.size(); i++){
+            for(int j=0; j<board[0].size(); j++){
+                if(board[i][j] == '.'){
+                    for(char c='1'; c<='9'; c++){
+                        if(valid(c, board, i, j)){
+                            board[i][j] = c;
+                            if(solve(board) == true) return true;
+                            else board[i][j]='.';
+                        }
+                    }
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+    
+    bool valid(char c, vector<vector<char>>& board, int row, int col){
+        for(int i=0; i<9; i++){
+            if(board[i][col] == c) return false;
+            if(board[row][i] == c) return false;
+            if(board[3*(row/3)+(i/3)][3*(col/3)+(i%3)] == c) return false;
+        }
+        return true;
+    }
+};