Initial commit: Pi calculation benchmark with 34 languages

- Added implementations for: bash, brainfuck, c, cpp, crystal, csharp, d, dart, elixir, erlang, fortran, go, haskell, java, javascript, julia, kotlin, objective-c, scala, typescript, lua, nim, odin, perl, php, python, r, ruby, rust, swift, zig, assembly, vimscript, wolfram
- All implementations use Machin's formula: π/4 = 4*arctan(1/5) - arctan(1/239)
- Build system with ./build.sh, test system with ./test.sh
- Performance testing with ./run_all.sh
- Comprehensive README.md explaining performance differences
- Test framework verifies correctness against known π values

cpp/cmd/build.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+# C++ Build Script
+
+SCRIPT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$SCRIPT_DIR"
+
+echo "=== C++ Build ==="
+echo ""
+
+# Kompilera C++-programmet med Boost (header-only, no linking needed)
+g++ -std=c++17 -I/opt/homebrew/opt/boost/include -o bin/print_hej src/print_hej.cpp
+
+if [ $? -eq 0 ]; then
+    echo "✓ Kompilering lyckades!"
+    echo "Binär: bin/print_hej"
+    echo ""
+    echo "För att köra:"
+    echo "  ./bin/print_hej [decimaler]"
+else
+    echo "✗ Kompilering misslyckades!"
+    exit 1
+fi

cpp/cmd/test.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+# C++ Unit Tests
+
+SCRIPT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$SCRIPT_DIR"
+
+echo "=== C++ Pi-beräkning Unit Tester ==="
+echo ""
+
+# Kompilera och kör pi_test
+g++ -o bin/pi_test src/pi_test.cpp -lgmp
+if [ $? -eq 0 ]; then
+    ./bin/pi_test
+    exit $?
+else
+    echo "✗ Kompilering av tester misslyckades!"
+    exit 1
+fi

cpp/src/pi_test.cpp

@@ -0,0 +1,75 @@
+#include <gtest/gtest.h>
+#include <cstdlib>
+#include <string>
+#include <array>
+#include <memory>
+
+const std::string SCRIPT_PATH = "/Users/einand/Code/test/cpp/print_hej";
+
+std::string run_script(const std::string& args = "") {
+    std::string cmd = SCRIPT_PATH;
+    if (!args.empty()) {
+        cmd += " " + args;
+    }
+    
+    std::array<char, 128> buffer;
+    std::string result;
+    std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd.c_str(), "r"), pclose);
+    
+    if (!pipe) {
+        throw std::runtime_error("popen() failed!");
+    }
+    
+    while (fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr) {
+        result += buffer.data();
+    }
+    
+    // Trim newline
+    if (!result.empty() && result.back() == '\n') {
+        result.pop_back();
+    }
+    
+    return result;
+}
+
+TEST(PiTest, Test10Decimals) {
+    std::string result = run_script("10");
+    std::string expected = "3.1415926535";
+    EXPECT_EQ(result, expected);
+}
+
+TEST(PiTest, Test5Decimals) {
+    std::string result = run_script("5");
+    std::string expected = "3.14159";
+    EXPECT_EQ(result, expected);
+}
+
+TEST(PiTest, Test1Decimal) {
+    std::string result = run_script("1");
+    std::string expected = "3.1";
+    EXPECT_EQ(result, expected);
+}
+
+TEST(PiTest, Test100Decimals) {
+    std::string result = run_script("100");
+    std::string expected = "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679";
+    EXPECT_EQ(result, expected);
+}
+
+TEST(PiTest, TestDefault100Decimals) {
+    std::string result = run_script();
+    std::string expected = "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679";
+    EXPECT_EQ(result, expected);
+}
+
+TEST(PiTest, Test10000Decimals) {
+    std::string result = run_script("10000");
+    // Check length: "3." + 10000 digits = 10002 characters
+    EXPECT_EQ(result.length(), 10002);
+    EXPECT_TRUE(result.substr(0, 7) == "3.14159");
+}
+
+int main(int argc, char **argv) {
+    testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}

cpp/src/print_hej.cpp

@@ -0,0 +1,95 @@
+#include <iostream>
+#include <cstdlib>
+#include <string>
+#include <boost/multiprecision/cpp_int.hpp>
+#include <boost/multiprecision/cpp_dec_float.hpp>
+
+namespace mp = boost::multiprecision;
+
+// Calculate arctan(1/x) using Taylor series with arbitrary precision
+// arctan(1/x) = 1/x - 1/(3*x^3) + 1/(5*x^5) - ...
+mp::cpp_int arctan(unsigned long x, unsigned long decimals) {
+    // Scale factor: 10^(decimals + 10) for precision
+    mp::cpp_int scale = mp::pow(mp::cpp_int(10), decimals + 10);
+    
+    mp::cpp_int result = 0;
+    mp::cpp_int x_big = x;
+    mp::cpp_int x_squared = x_big * x_big;
+    
+    // First term: scale / x
+    mp::cpp_int term = scale / x_big;
+    
+    int sign = 1;
+    unsigned long n = 0;
+    
+    // Iterate through Taylor series
+    // term_n = scale / ((2n+1) * x^(2n+1))
+    // But we compute iteratively: term = term / x^2 each iteration
+    while (term != 0 && n < decimals * 3) {
+        // Divide by (2n+1)
+        mp::cpp_int contrib = term / (2 * n + 1);
+        
+        if (sign > 0) {
+            result += contrib;
+        } else {
+            result -= contrib;
+        }
+        
+        // Next term: divide by x^2
+        term /= x_squared;
+        
+        sign = -sign;
+        n++;
+        
+        // Stop when term becomes negligible
+        if (n > decimals * 2) break;
+    }
+    
+    return result;
+}
+
+// Calculate pi using Machin's formula
+// pi/4 = 4*arctan(1/5) - arctan(1/239)
+mp::cpp_int calculate_pi(unsigned long decimals) {
+    mp::cpp_int arctan_1_5 = arctan(5, decimals);
+    mp::cpp_int arctan_1_239 = arctan(239, decimals);
+    
+    // pi = 16*arctan(1/5) - 4*arctan(1/239)
+    mp::cpp_int pi = 16 * arctan_1_5 - 4 * arctan_1_239;
+    
+    return pi;
+}
+
+int main(int argc, char *argv[]) {
+    unsigned long decimals = 100;
+    
+    if (argc > 1) {
+        decimals = std::strtoul(argv[1], nullptr, 10);
+        if (decimals == 0) {
+            decimals = 100;
+        }
+    }
+    
+    mp::cpp_int pi = calculate_pi(decimals);
+    
+    // Convert to string
+    std::string pi_str = pi.convert_to<std::string>();
+    
+    // Print with decimal point
+    if (!pi_str.empty()) {
+        std::cout << '3';
+        if (decimals > 0) {
+            std::cout << '.';
+            // Print decimals, skipping the leading "3"
+            size_t start = 1;
+            size_t end = start + decimals;
+            if (end > pi_str.length()) end = pi_str.length();
+            for (size_t i = start; i < end && i < pi_str.length(); i++) {
+                std::cout << pi_str[i];
+            }
+        }
+        std::cout << '\n';
+    }
+    
+    return 0;
+}