From b166b0ef70bf33aa219775be1a9cb56484379c4c Mon Sep 17 00:00:00 2001
From: wieerwill <robert.jeutter@gmx.de>
Date: Sat, 2 Dec 2023 12:14:52 +0100
Subject: [PATCH] solve Day01 with cpp

---
 .gitignore             | 34 ++++++++++++++++
 Day01/cpp/solution.cpp | 90 ++++++++++++++++++++++++++++++++++++++++++
 README.md              | 12 +++++-
 3 files changed, 134 insertions(+), 2 deletions(-)
 create mode 100644 Day01/cpp/solution.cpp

diff --git a/.gitignore b/.gitignore
index 44baee0..00f715f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -174,4 +174,38 @@ Cargo.lock
 # MSVC Windows builds of rustc generate these, which store debugging information
 *.pdb
 
+# Prerequisites
+*.d
+
+# Compiled Object files
+*.slo
+*.lo
+*.o
+*.obj
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Compiled Dynamic libraries
+*.so
+*.dylib
+*.dll
+
+# Fortran module files
+*.mod
+*.smod
+
+# Compiled Static libraries
+*.lai
+*.la
+*.a
+*.lib
+
+# Executables
+*.exe
+*.out
+*.app
+
+solution
 helper.md
\ No newline at end of file
diff --git a/Day01/cpp/solution.cpp b/Day01/cpp/solution.cpp
new file mode 100644
index 0000000..a2a391d
--- /dev/null
+++ b/Day01/cpp/solution.cpp
@@ -0,0 +1,90 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include <vector>
+#include <map>
+#include <cassert>
+
+std::vector<int> extractDigits(const std::string& line) {
+    std::map<std::string, int> digitMap = {
+        {"zero", 0}, {"one", 1}, {"two", 2}, {"three", 3}, {"four", 4},
+        {"five", 5}, {"six", 6}, {"seven", 7}, {"eight", 8}, {"nine", 9}
+    };
+    for (int i = 0; i <= 9; ++i) {
+        digitMap[std::to_string(i)] = i;
+    }
+
+    std::vector<int> digitsFound;
+    size_t i = 0;
+    while (i < line.length()) {
+        bool matched = false;
+        for (const auto& pair : digitMap) {
+            if (line.substr(i, pair.first.length()) == pair.first) {
+                digitsFound.push_back(pair.second);
+                i += pair.first.length() - 1;
+                matched = true;
+                break;
+            }
+        }
+        i++;
+    }
+
+    return digitsFound;
+}
+
+int extractCalibrationValue(const std::string& line) {
+    std::vector<int> digits = extractDigits(line);
+    if (!digits.empty()) {
+        return digits.front() * 10 + digits.back();
+    }
+    return 0;
+}
+
+int calculateTotalCalibrationValue(const std::string& filePath) {
+    std::ifstream file(filePath);
+    if (!file.is_open()) {
+        throw std::runtime_error("Unable to open file: " + filePath);
+    }
+
+    std::string line;
+    int totalValue = 0;
+    while (std::getline(file, line)) {
+        totalValue += extractCalibrationValue(line);
+    }
+
+    return totalValue;
+}
+
+void test() {
+    std::cout << "Starting Tests" << std::endl;
+    std::vector<std::string> testLines = {
+        "two1nine",
+        "eightwothree",
+        "abcone2threexyz",
+        "xtwone3four",
+        "4nineeightseven2",
+        "zoneight234",
+        "7pqrstsixteen"
+    };
+    std::vector<int> expectedResults = {29, 83, 13, 24, 42, 14, 76};
+
+    for (size_t i = 0; i < testLines.size(); ++i) {
+        int result = extractCalibrationValue(testLines[i]);
+        assert(result == expectedResults[i]);
+        std::cout << "Line: '" << testLines[i] << "', Calibration Value: " << result << std::endl;
+    }
+    std::cout << "Finished Tests" << std::endl << std::endl;
+}
+
+int main() {
+    try {
+        test();
+        int totalValue = calculateTotalCalibrationValue("../input.txt");
+        std::cout << "Total Calibration Value from input.txt: " << totalValue << std::endl;
+    } catch (const std::exception& e) {
+        std::cerr << "Error: " << e.what() << std::endl;
+    }
+
+    return 0;
+}
diff --git a/README.md b/README.md
index 0608c98..0c0c38b 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,7 @@ For example:
 
 ```bash
 cd Day01/python
-python3 part2.py test.txt # for testing
+python3 part2.py test.txt # for testing (not all Days will have that)
 python3 part2.py
 ```
 
@@ -61,7 +61,15 @@ You can either test or run the solution:
 ```bash
 cd Day01/rust
 cargo test #running tests
-cargo run
+cargo run # run with the actual input file
+```
+
+## C++
+Install a C++ compiler like g++ on your machine. Then:
+```bash
+cd Day01/cpp
+g++ -o solution solution.cpp # compile
+./solution #run the binary
 ```
 
 ## JavaScript