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/* ************************************************************** * C++ Mathematical Expression Toolkit Library * * * * ExprTk Recursive Fibonacci Example * * 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 recursive_fibonacci_example() { 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; exprtk::rtl::io::package io_package; symbol_table_t symbol_table; symbol_table.add_package(io_package); compositor_t compositor(symbol_table); compositor.add( function_t("fibonacci") .var("n") .expression ( " (n < 2) ? n : fibonacci(n - 1) + fibonacci(n - 2); " )); const std::string fibonacci_program = " const var n := 35; " " " " for (var i := 0; i <= n; i += 1) " " { " " var fib_i := fibonacci(i); " " println('fib(',i,') = ', fib_i); " " } "; expression_t expression; expression.register_symbol_table(symbol_table); parser_t parser; parser.compile(fibonacci_program,expression); exprtk::timer timer; timer.start(); expression.value(); timer.stop(); printf("Total time: %8.4fsec\n",timer.time()); } int main() { recursive_fibonacci_example(); return 0; }