Merge pull request #197 from JitinSaxenaa/sudoku

Sudoku

Author: Pradeepsingh61

CPP/data_structures/graphs/graph/number of provinces.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+private:
+    void dfs(int node, vector<int> adjLs[], int vis[]) {
+        vis[node] = 1;
+        for (auto it : adjLs[node]) {
+            if (!vis[it]) {
+                dfs(it, adjLs, vis);
+            }
+        }
+    }
+public:
+    int numProvinces(vector<vector<int>> adj, int V) {
+        vector<int> adjLs[V];
+        for (int i = 0; i < V; i++) {
+            for (int j = 0; j < V; j++) {
+                if (adj[i][j] == 1 && i != j) {
+                    adjLs[i].push_back(j);
+                    adjLs[j].push_back(i);
+                }
+            }
+        }
+        int vis[V] = {0};
+        int cnt = 0;
+        for (int i = 0; i < V; i++) {
+            if (!vis[i]) {
+                cnt++;
+                dfs(i, adjLs, vis);
+            }
+        }
+        return cnt;
+    }
+};
+
+// Example usage
+int main() {
+    vector<vector<int>> adj = {
+        {1,1,0},
+        {1,1,0},
+        {0,0,1}
+    };
+    int V = adj.size();
+    
+    Solution sol;
+    cout << "Number of provinces: " << sol.numProvinces(adj, V) << endl;
+    return 0;
+}

CPP/data_structures/graphs/graph/provinces.cpp

@@ -0,0 +1,79 @@
+package Java.algorithms.arrays;
+
+public class SudokuSolver {
+
+    private static final int SIZE = 9;
+
+    public void solveSudoku(char[][] board) {
+        solve(board);
+    }
+
+    private boolean solve(char[][] board) {
+        for (int row = 0; row < SIZE; row++) {
+            for (int col = 0; col < SIZE; col++) {
+                if (board[row][col] == '.') {
+                    for (char num = '1'; num <= '9'; num++) {
+                        if (isValid(board, row, col, num)) {
+                            board[row][col] = num;
+                            if (solve(board)) return true;
+                            board[row][col] = '.';
+                        }
+                    }
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    private boolean isValid(char[][] board, int row, int col, char num) {
+        for (int i = 0; i < SIZE; i++) {
+            if (board[row][i] == num || board[i][col] == num) return false;
+        }
+        int startRow = (row / 3) * 3;
+        int startCol = (col / 3) * 3;
+        for (int i = startRow; i < startRow + 3; i++) {
+            for (int j = startCol; j < startCol + 3; j++) {
+                if (board[i][j] == num) return false;
+            }
+        }
+        return true;
+    }
+
+    private void printBoard(char[][] board) {
+        for (int i = 0; i < SIZE; i++) {
+            for (int j = 0; j < SIZE; j++) {
+                System.out.print(board[i][j] + " ");
+            }
+            System.out.println();
+        }
+    }
+
+    /**
+     * Simulates a C/C++ style int main() function
+     */
+    public static int run() {
+        char[][] 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'}
+        };
+
+        SudokuSolver solver = new SudokuSolver();
+        solver.solveSudoku(board);
+        solver.printBoard(board);
+
+        return 0; // success
+    }
+
+    public static void main(String[] args) {
+        int status = run();
+        System.exit(status);
+    }
+}