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/* ************************************************************** * C++ Mathematical Expression Toolkit Library * * * * ExprTk Magic Square * * Author: Arash Partow (1999-2024) * * URL: https://www.partow.net/programming/exprtk/index.html * * * * Copyright notice: * * Free use of the Mathematical Expression Toolkit Library is * * permitted under the guidelines and in accordance with the * * most current version of the MIT License. * * https://www.opensource.org/licenses/MIT * * SPDX-License-Identifier: MIT * * * ************************************************************** */ #include #include "exprtk.hpp" template void magic_square() { typedef exprtk::symbol_table symbol_table_t; typedef exprtk::expression expression_t; typedef exprtk::parser parser_t; typedef exprtk::function_compositor compositor_t; typedef typename compositor_t::function function_t; const T n = T(15); std::vector square(static_cast(n * n), T(0)); exprtk::rtl::io::package io_package; symbol_table_t symbol_table; symbol_table.add_constant("n", n); symbol_table.add_vector ("square", square); symbol_table.add_function("print_digit", [](T v) ->T { printf(" %03d ",static_cast(v)); return 0; }); symbol_table.add_package (io_package); compositor_t compositor(symbol_table); compositor.load_variables(true); compositor.load_vectors (true); compositor.add( function_t("get_square") .vars("col", "row") .expression ( " square[row * n + col]; " )); compositor.add( function_t("set_square") .vars("col", "row", "value") .expression ( " square[row * n + col] := value; " )); compositor.add( function_t("display_magic_square") .expression ( " for (var row := 0; row < n; row += 1) " " { " " for (var col := 0; col < n; col += 1) " " { " " print_digit(get_square(col,row)); " " }; " " " " println(''); " " } " )); const std::string magic_square_program = " var num := 1; " " var i := 0; " " var j := floor(n / 2); " " " " while (num <= (n * n)) " " { " " set_square(i, j, num); " " num += 1; " " " " var i_next := (i - 1 + n) % n; " " var j_next := (j + 1) % n; " " " " if (get_square(i_next, j_next) != 0) " " { " " i := (i + 1) % n; " " } " " else " " { " " i := i_next; " " j := j_next; " " } " " }; " " " " println('sum: ', n * (n^2 + 1) / 2); " " " " display_magic_square(); "; expression_t expression; expression.register_symbol_table(symbol_table); parser_t parser; parser.compile(magic_square_program,expression); expression.value(); } int main() { magic_square(); return 0; }