Played with chapter two examples

chap2/chap2.py

@@ -0,0 +1,46 @@
+def searchSubsets(k, n, subset):
+  if k == n+1:
+    # process subset
+    print(subset)
+  else:
+    # include k in the subset
+    subset.append(k)
+    searchSubsets(k+1,n,subset)
+    subset.pop()
+    # don’t include k in the subset
+    searchSubsets(k+1, n, subset)
+    
+def searchPermutations(n,permutation,chosen):
+  if len(permutation) == n:
+    print(permutation)
+  else:
+    for i in range (1,n+1):
+        if chosen[i]:
+          continue
+        chosen[i] = True
+        permutation.append(i)
+        searchPermutations(n,permutation,chosen)
+        chosen[i] = False
+        permutation.pop()
+
+def searchQueens(y, n, col, diag1, diag2):
+    if y == n:
+        return 1  # Return 1 to count a valid arrangement
+    count = 0
+    for x in range(n):
+        if col[x] or diag1[x + y] or diag2[x - y + n - 1]:
+            continue
+        col[x] = diag1[x + y] = diag2[x - y + n - 1] = True
+        count += searchQueens(y + 1, n, col, diag1, diag2)
+        col[x] = diag1[x + y] = diag2[x - y + n - 1] = False
+    return count
+
+if __name__ == "__main__":
+  searchSubsets(1,4,list[int]())
+  searchPermutations(4,list[int](),[False]*5)
+  n = 16  # Replace with the size of the board
+  col = [False] * n
+  diag1 = [False] * (2 * n - 1)
+  diag2 = [False] * (2 * n - 1)
+  solution_count = searchQueens(0, n, col, diag1, diag2)
+  print(solution_count)