Soduko

new_soduko_lover.cpp

@@ -0,0 +1,81 @@
+#include <iostream>
+#define N 9
+using namespace std;
+int grid[N][N] = {
+   {3, 0, 6, 5, 0, 8, 4, 0, 0},
+   {5, 2, 0, 0, 0, 0, 0, 0, 0},
+   {0, 8, 7, 0, 0, 0, 0, 3, 1},
+   {0, 0, 3, 0, 1, 0, 0, 8, 0},
+   {9, 0, 0, 8, 6, 3, 0, 0, 5},
+   {0, 5, 0, 0, 9, 0, 6, 0, 0},
+   {1, 3, 0, 0, 0, 0, 2, 5, 0},
+   {0, 0, 0, 0, 0, 0, 0, 7, 4},
+   {0, 0, 5, 2, 0, 6, 3, 0, 0}
+};
+bool isPresentInCol(int col, int num){ //check whether num is present in col or not
+   for (int row = 0; row < N; row++)
+      if (grid[row][col] == num)
+         return true;
+   return false;
+}
+bool isPresentInRow(int row, int num){ //check whether num is present in row or not
+   for (int col = 0; col < N; col++)
+      if (grid[row][col] == num)
+         return true;
+   return false;
+}
+bool isPresentInBox(int boxStartRow, int boxStartCol, int num){
+//check whether num is present in 3x3 box or not
+   for (int row = 0; row < 3; row++)
+      for (int col = 0; col < 3; col++)
+         if (grid[row+boxStartRow][col+boxStartCol] == num)
+            return true;
+   return false;
+}
+void sudokuGrid(){ //print the sudoku grid after solve
+   for (int row = 0; row < N; row++){
+      for (int col = 0; col < N; col++){
+         if(col == 3 || col == 6)
+            cout << " | ";
+         cout << grid[row][col] <<" ";
+      }
+      if(row == 2 || row == 5){
+         cout << endl;
+         for(int i = 0; i<N; i++)
+            cout << "---";
+      }
+      cout << endl;
+   }
+}
+bool findEmptyPlace(int &row, int &col){ //get empty location and update row and column
+   for (row = 0; row < N; row++)
+      for (col = 0; col < N; col++)
+         if (grid[row][col] == 0) //marked with 0 is empty
+            return true;
+   return false;
+}
+bool isValidPlace(int row, int col, int num){
+   //when item not found in col, row and current 3x3 box
+   return !isPresentInRow(row, num) && !isPresentInCol(col, num) && !isPresentInBox(row - row%3 ,
+col - col%3, num);
+}
+bool solveSudoku(){
+   int row, col;
+   if (!findEmptyPlace(row, col))
+      return true; //when all places are filled
+   for (int num = 1; num <= 9; num++){ //valid numbers are 1 - 9
+      if (isValidPlace(row, col, num)){ //check validation, if yes, put the number in the grid
+         grid[row][col] = num;
+         if (solveSudoku()) //recursively go for other rooms in the grid
+            return true;
+         grid[row][col] = 0; //turn to unassigned space when conditions are not satisfied
+      }
+   }
+   return false;
+}
+int main(){
+   if (solveSudoku() == true)
+      sudokuGrid();
+   else
+      cout << "No solution exists";
+}

program/CPP/reversell.cpp

@@ -0,0 +1,74 @@
+#include <iostream>
+using namespace std;
+
+/* Link list node */
+struct Node {
+    int data;
+    struct Node* next;
+    Node(int data)
+    {
+        this->data = data;
+        next = NULL;
+    }
+};
+
+struct LinkedList {
+    Node* head;
+    LinkedList() { head = NULL; }
+
+    /* Function to reverse the linked list */
+    void reverse()
+    {
+        // Initialize current, previous and next pointers
+        Node* current = head;
+        Node *prev = NULL, *next = NULL;
+
+        while (current != NULL) {
+            // Store next
+            next = current->next;
+            // Reverse current node's pointer
+            current->next = prev;
+            // Move pointers one position ahead.
+            prev = current;
+            current = next;
+        }
+        head = prev;
+    }
+
+    /* Function to print linked list */
+    void print()
+    {
+        struct Node* temp = head;
+        while (temp != NULL) {
+            cout << temp->data << " ";
+            temp = temp->next;
+        }
+    }
+
+    void push(int data)
+    {
+        Node* temp = new Node(data);
+        temp->next = head;
+        head = temp;
+    }
+};
+
+/* Driver code*/
+int main()
+{
+    /* Start with the empty list */
+    LinkedList ll;
+    ll.push(20);
+    ll.push(4);
+    ll.push(15);
+    ll.push(85);
+
+    cout << "Given linked list\n";
+    ll.print();
+
+    ll.reverse();
+
+    cout << "\nReversed linked list \n";
+    ll.print();
+    return 0;
+}