Add solution to day 2

2025/Cpp/Day02/Day02.cpp

@@ -3,16 +3,133 @@
 #include <iostream>
 #include <cassert>
 #include <string>
+#include <cstring>
+#include <sstream>
+
+class Range {
+public:
+    using range_t = long long;
+
+    Range(range_t minValue, range_t maxValue)
+        : mMinValue(minValue)
+        , mMaxValue(maxValue)
+    {
+	}
+
+    inline range_t left() const { return mMinValue; }
+    inline range_t right() const { return mMaxValue; }
+
+private:
+    const range_t mMinValue;
+	const range_t mMaxValue;
+};
 
 class Day02Solution : public AdventHelpers::AdventOfCodeSolution
 {
 public:
+	using RangeList = std::vector<Range>;
+
+    static RangeList ParseLine(std::string line) {
+        size_t index = 0;
+
+        RangeList ranges;
+
+        while (line.length() > 0) {
+            std::string left, right;
+
+            size_t start = 0;
+			size_t leftEnd = line.substr(start).find('-');
+
+            size_t rightEnd = line.substr(leftEnd).find(',');
+            if (rightEnd == std::string::npos) rightEnd = line.length() - 1;
+
+            left = line.substr(start, leftEnd);
+            right = line.substr(leftEnd+1, rightEnd-1);
+            
+            ranges.push_back(Range(std::stoll(left), std::stoll(right)));
+
+            line.erase(0, leftEnd + rightEnd + 1);
+        }
+
+        return ranges;
+    }
+
+    // An ID is invalid if the first half and the second half match.
+    // It necessarily must be even.
+    static bool isValidPart01(const std::string number) {
+        if (number.length() % 2 == 0) {
+			const size_t halfLength = number.length() / 2;
+
+			std::string left = number.substr(0, halfLength);
+			std::string right = number.substr(halfLength);
+
+            if (left.compare(right) == 0) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    // In part 2, an id is invalid if it has some sequence repeated at least twice.
+    // 111 = 1 three times, invalid
+    // 121212 = 12 three times, invalid
+    // 123123 = same as above, 123 twice
+    static bool isValidPart02(const std::string number) {
+        // Once we hit half the length, it must be the same on both sides
+        const size_t halfLen = number.length() / 2;
+
+        // Start from one character and work up
+        for (int i = 0; i < halfLen; i++) {
+            const auto substr = number.substr(0, i + 1);
+            std::string temp(number);
+
+            while (temp.substr(0, substr.length()).compare(substr) == 0) {
+                temp.erase(0, substr.length());
+            }
+            
+            if (temp.length() == 0) return false;
+        }
+
+        return true;
+    }
+
     virtual std::string SolveProblem01(AdventHelpers::InputFileHelper& inputFile) override {
-        return "todo";
+        std::string line = inputFile.getLine(0);
+        
+		auto ranges = ParseLine(line);
+        Range::range_t sum = 0;
+
+        for (const auto& range : ranges) {
+            auto left = range.left();
+            auto right = range.right();
+
+            for (Range::range_t i = left; i <= right; i++) {
+                if (!isValidPart01(std::to_string(i))) 
+                    sum += i;
+            }
+        }
+
+        return std::to_string(sum);
     }
 
     virtual std::string SolveProblem02(AdventHelpers::InputFileHelper& inputFile) override {
-        return "todo";
+        std::string line = inputFile.getLine(0);
+         
+        auto ranges = ParseLine(line);
+        Range::range_t sum = 0;
+
+        for (const auto& range : ranges) {
+            auto left = range.left();
+            auto right = range.right();
+
+            for (Range::range_t i = left; i <= right; i++) {
+                if (!isValidPart02(std::to_string(i)))
+                    sum += i;
+            }
+        }
+
+        return std::to_string(sum);
     }
 };
 

2025/Cpp/Day02/Day02.vcxproj

@@ -79,6 +79,7 @@
       <PreprocessorDefinitions>WIN32;_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
       <LanguageStandard>stdcpp20</LanguageStandard>
+      <OpenMPSupport>true</OpenMPSupport>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -94,6 +95,7 @@
       <PreprocessorDefinitions>WIN32;NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
       <LanguageStandard>stdcpp20</LanguageStandard>
+      <OpenMPSupport>true</OpenMPSupport>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -107,6 +109,7 @@
       <PreprocessorDefinitions>_DEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
       <LanguageStandard>stdcpp20</LanguageStandard>
+      <OpenMPSupport>true</OpenMPSupport>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>
@@ -122,6 +125,7 @@
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <ConformanceMode>true</ConformanceMode>
       <LanguageStandard>stdcpp20</LanguageStandard>
+      <OpenMPSupport>true</OpenMPSupport>
     </ClCompile>
     <Link>
       <SubSystem>Console</SubSystem>

2025/Cpp/Day02/example-input.txt

@@ -0,0 +1 @@
+11-22,95-115,998-1012,1188511880-1188511890,222220-222224,1698522-1698528,446443-446449,38593856-38593862,565653-565659,824824821-824824827,2121212118-2121212124

2025/Cpp/Day02/puzzle-input.txt

@@ -0,0 +1 @@
+3737332285-3737422568,5858547751-5858626020,166911-236630,15329757-15423690,753995-801224,1-20,2180484-2259220,24-47,73630108-73867501,4052222-4199117,9226851880-9226945212,7337-24735,555454-591466,7777695646-7777817695,1070-2489,81504542-81618752,2584-6199,8857860-8922218,979959461-980003045,49-128,109907-161935,53514821-53703445,362278-509285,151-286,625491-681593,7715704912-7715863357,29210-60779,3287787-3395869,501-921,979760-1021259