Add Sudoku Solver Problem

Author: Ashok-Bhatt

Sudoku_Solver/submission1.cpp

@@ -0,0 +1,43 @@
+class Solution {
+private:
+    bool isValid(vector<vector<char>>& board, int position, int digit){
+        int x = position/9, y = position%9, blockX = x/3, blockY = y/3;
+
+        for (int i=0; i<9; i++){
+            if (board[x][i]==digit+'0' || board[i][y]==digit+'0' || board[blockX*3+i/3][blockY*3+i%3]==digit+'0'){
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    bool solve(vector<vector<char>>& board, int position){
+
+        if (position == 81){
+            return true;
+        }
+
+        if (board[position/9][position%9] != '.'){
+            return solve(board, position+1);
+        }
+
+        for (int digit=1; digit<=9; digit++){
+            if (isValid(board, position, digit)){
+                board[position/9][position%9] = digit+'0';
+                if (solve(board, position+1)){
+                    return true;
+                }
+                board[position/9][position%9] = '.';
+            }
+        }
+
+        return false;
+    }
+
+public:
+    void solveSudoku(vector<vector<char>>& board) {
+        int position = 0;
+        solve(board, position);
+    }
+};