N_Queen

demo.cpp

@@ -0,0 +1,56 @@
+#include <iostream>
+
+#include <cstdio>
+
+using namespace std;
+
+int main()
+{
+
+  const int DIMEN = 24;
+
+
+  char canvas [DIMEN][DIMEN] = {{0}};
+
+  for(int row = 0; row < DIMEN; row++)
+  {
+
+    for(int col = 0; col < DIMEN; col++)
+    {
+
+      int x = col - DIMEN/2;
+
+      int y = DIMEN/2 - row;
+
+
+      int sumsq = x*x + y*y;
+
+      if((95 < sumsq) && (sumsq < 105))
+      {
+
+        canvas[row][col] = '*';
+
+      }
+
+    }
+
+  }
+
+  for(int row = 0; row < DIMEN; row++)
+  {
+
+    for(int col = 0; col < DIMEN; col++)
+    {
+
+
+      printf("%c ", canvas[row][col]);
+
+    }
+
+    cout << endl;
+
+  }
+
+  return 0;
+
+}

ktour.cpp

@@ -0,0 +1,147 @@
+
+#include <iostream>
+using namespace std;
+int m, n, k;
+int count = 0;
+void makeBoard(char **board)
+{
+    for (int i = 0; i < m; i++)
+    {
+        for (int j = 0; j < n; j++)
+        {
+            board[i][j] = '_';
+        }
+    }
+}
+
+void displayBoard(char **board)
+{
+    cout << endl
+         << endl;
+    for (int i = 0; i < m; i++)
+    {
+        for (int j = 0; j < n; j++)
+        {
+            cout << " " << board[i][j] << " ";
+        }
+        cout << endl;
+    }
+}
+
+void attack(int i, int j, char a,
+            char **board)
+{
+
+    if ((i + 2) < m && (j - 1) >= 0)
+    {
+        board[i + 2][j - 1] = a;
+    }
+    if ((i - 2) >= 0 && (j - 1) >= 0)
+    {
+        board[i - 2][j - 1] = a;
+    }
+    if ((i + 2) < m && (j + 1) < n)
+    {
+        board[i + 2][j + 1] = a;
+    }
+    if ((i - 2) >= 0 && (j + 1) < n)
+    {
+        board[i - 2][j + 1] = a;
+    }
+    if ((i + 1) < m && (j + 2) < n)
+    {
+        board[i + 1][j + 2] = a;
+    }
+    if ((i - 1) >= 0 && (j + 2) < n)
+    {
+        board[i - 1][j + 2] = a;
+    }
+    if ((i + 1) < m && (j - 2) >= 0)
+    {
+        board[i + 1][j - 2] = a;
+    }
+    if ((i - 1) >= 0 && (j - 2) >= 0)
+    {
+        board[i - 1][j - 2] = a;
+    }
+}
+
+bool canPlace(int i, int j, char **board)
+{
+    if (board[i][j] == '_')
+        return true;
+    else
+        return false;
+}
+
+void place(int i, int j, char k, char a,
+           char **board, char **new_board)
+{
+    for (int y = 0; y < m; y++)
+    {
+        for (int z = 0; z < n; z++)
+        {
+            new_board[y][z] = board[y][z];
+        }
+    }
+    new_board[i][j] = k;
+    attack(i, j, a, new_board);
+}
+
+void kkn(int k, int sti, int stj, char **board)
+{
+    if (k == 0)
+    {
+        displayBoard(board);
+        count++;
+    }
+    else
+    {
+        for (int i = sti; i < m; i++)
+        {
+            for (int j = stj; j < n; j++)
+            {
+
+                if (canPlace(i, j, board))
+                {
+
+                    char **new_board = new char *[m];
+                    for (int x = 0; x < m; x++)
+                    {
+                        new_board[x] = new char[n];
+                    }
+                    place(i, j, 'K', 'A', board, new_board);
+
+                    kkn(k - 1, i, j, new_board);
+
+                    for (int x = 0; x < m; x++)
+                    {
+                        delete[] new_board[x];
+                    }
+                    delete[] new_board;
+                }
+            }
+            stj = 0;
+        }
+    }
+}
+
+int main()
+{
+    m = 4, n = 3, k = 6;
+
+    char **board = new char *[m];
+    for (int i = 0; i < m; i++)
+    {
+        board[i] = new char[n];
+    }
+
+    makeBoard(board);
+
+    kkn(k, 0, 0, board);
+
+    cout << endl
+         << "Total number of solutions : "
+         << count;
+    return 0;
+}

new.c

@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <math.h>
+
+#define MAX 10
+
+int x[MAX];
+
+int Place(int k, int i)
+{
+    for (int j = 1; j <= k - 1; j++)
+    {
+        if (x[j] == i || (abs(x[j] - i) == abs(j - k)))
+        {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+void display(int n)
+{
+    printf("Arrangement\n");
+    for (int i = 1; i <= n; i++)
+    {
+        for (int j = 1; j <= n; j++)
+        {
+            if (x[i] != j)
+            {
+                printf(".");
+            }
+            else
+            {
+                printf("Q");
+            }
+        }
+        printf("\n");
+    }
+}
+
+void nqueens(int k, int n)
+{
+
+    for (int i = 1; i <= n; i++)
+    {
+        if (Place(k, i))
+        {
+            x[k] = i;
+            if (k == n)
+            {
+                display(n);
+            }
+            else
+            {
+                nqueens(k + 1, n);
+            }
+        }
+    }
+}
+
+int main()
+{
+    int n = 0;
+    printf("Enter the size of board\n");
+    scanf("%d", &n);
+    nqueens(1, n);
+    return 0;
+}