chore: use iwyu on backtracking/**.cpp

Author: realstealthninja

backtracking/generate_parentheses.cpp

@@ -11,9 +11,10 @@
 
  */
 
-#include <cassert>   /// for assert
-#include <iostream>  /// for I/O operation
-#include <vector>    /// for vector container
+#include <cassert>   // for assert
+#include <iostream>  // for char_traits, operator<<, basic_ostream, cout
+#include <vector>    // for allocator, vector, operator==
+#include <string>    // for basic_string, string, operator+, operator==
 
 /**
  * @brief Backtracking algorithms

backtracking/graph_coloring.cpp

@@ -18,9 +18,9 @@
  * @author [David Leal](https://github.com/Panquesito7)
  */
 
-#include <array>     /// for std::array
-#include <iostream>  /// for IO operations
-#include <vector>    /// for std::vector
+#include <array>     // for array
+#include <cstddef>   // for size_t
+#include <iostream>  // for operator<<, cout, basic_ostream, basic_ostream::...
 
 /**
  * @namespace backtracking

backtracking/knight_tour.cpp

@@ -13,8 +13,9 @@
  * @author [Nikhil Arora](https://github.com/nikhilarora068)
  * @author [David Leal](https://github.com/Panquesito7)
  */
-#include <array>     /// for std::array
-#include <iostream>  /// for IO operations
+#include <array>     // for array
+#include <cstddef>   // for size_t
+#include <iostream>  // for char_traits, operator<<, basic_ostream, cout
 
 /**
  * @namespace backtracking

backtracking/minimax.cpp

@@ -16,10 +16,11 @@
  * @author [Gleison Batista](https://github.com/gleisonbs)
  * @author [David Leal](https://github.com/Panquesito7)
  */
-#include <algorithm>  /// for std::max, std::min
-#include <array>      /// for std::array
-#include <cmath>      /// for log2
-#include <iostream>   /// for IO operations
+#include <algorithm>  // for max, min
+#include <array>      // for array
+#include <cmath>      // for log2
+#include <cstddef>    // for size_t
+#include <iostream>   // for char_traits, basic_ostream, basic_ostream::oper...
 
 /**
  * @namespace backtracking

backtracking/n_queens.cpp

@@ -15,8 +15,9 @@
  * @author [David Leal](https://github.com/Panquesito7)
  *
  */
-#include <array>
-#include <iostream>
+#include <array>     // for array
+#include <cstddef>   // for size_t
+#include <iostream>  // for operator<<, basic_ostream, cout, basic_ostream::...
 
 /**
  * @namespace backtracking

backtracking/n_queens_all_solution_optimised.cpp

@@ -7,8 +7,9 @@
  * @author [David Leal](https://github.com/Panquesito7)
  */
 
-#include <array>
-#include <iostream>
+#include <array>     // for array
+#include <cstddef>   // for size_t
+#include <iostream>  // for cout, basic_ostream, endl, basic_ostream::operat...
 
 /**
  * @namespace backtracking

backtracking/nqueen_print_all_solutions.cpp

@@ -7,8 +7,10 @@
  * @author [David Leal](https://github.com/Panquesito7)
  *
  */
-#include <array>     /// for std::array
-#include <iostream>  /// for IO operations
+#include <array>     // for array
+#include <cstddef>   // for size_t
+#include <iostream>  // for cout, basic_ostream, endl, basic_ostream::operat...
+
 
 /**
  * @namespace backtracking

backtracking/rat_maze.cpp

@@ -16,9 +16,10 @@
  * @author [David Leal](https://github.com/Panquesito7)
  */
 
-#include <array>     /// for std::array
-#include <cassert>   /// for assert
-#include <iostream>  /// for IO operations
+#include <array>     // for array
+#include <cassert>   // for assert
+#include <cstddef>   // for size_t
+#include <iostream>  // for cout, basic_ostream, basic_ostream::operator<<
 
 /**
  * @namespace backtracking

backtracking/sudoku_solver.cpp

@@ -15,8 +15,10 @@
  * @author [DarthCoder3200](https://github.com/DarthCoder3200)
  * @author [David Leal](https://github.com/Panquesito7)
  */
-#include <array>     /// for assert
-#include <iostream>  /// for IO operations
+#include <array>     // for array
+#include <cstddef>   // for size_t
+#include <iostream>  // for basic_ostream, char_traits, cout, operator<<
+
 
 /**
  * @namespace backtracking

backtracking/wildcard_matching.cpp

@@ -11,10 +11,11 @@
  * @author [Swastika Gupta](https://github.com/Swastyy)
  */
 
-#include <cassert>   /// for assert
-#include <cstdint>   /// for integral typedefs
-#include <iostream>  /// for IO operations
-#include <vector>    /// for std::vector
+#include <cassert>   // for assert
+#include <cstdint>   // for uint32_t, int64_t
+#include <iostream>  // for basic_ostream, operator<<, char_traits, cout, endl
+#include <vector>    // for vector
+#include <string>    // for basic_string, string
 
 /**
  * @namespace backtracking