Adding exam part 1/4

Exam/IKT203-main/Portfolio/SharedLib/ReadGraph.cpp

@@ -0,0 +1,109 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <string>
+#include "SharedLib.h"
+#include "FileReaderUtils.h"
+
+// --- Enum for the parser's state ---
+enum class EParseState
+{
+	NONE,
+	NODES,
+	EDGES
+};
+
+void readGraphFromFile(const std::string& aFilename, FNodeRead aOnNodeRead, FEdgeRead aOnEdgeRead)
+{
+	if (aFilename.empty()) return;
+
+	std::ifstream file(aFilename);
+	if (!file.is_open())
+	{
+		// Optional: print an error
+		// std::cerr << "Error: Could not open file " << aFilename << std::endl;
+		return;
+	}
+
+	std::string line;
+	EParseState currentState = EParseState::NONE;
+	int totalCount = 0;
+	int currentIndex = 0;
+	bool keepReading = true;
+
+	while (keepReading && std::getline(file, line))
+	{
+		if (line.empty()) continue;
+
+		if (line[0] == '[')
+		{
+			// --- 2. USE THE SHARED FUNCTION ---
+			totalCount = GetRecordCount(line);
+			currentIndex = 0;
+
+			if (line.find("[NODES") != std::string::npos)
+			{
+				currentState = EParseState::NODES;
+				continue;
+			}
+			else if (line.find("[EDGES") != std::string::npos)
+			{
+				currentState = EParseState::EDGES;
+				continue;
+			}
+			// If it's a comment or other header, reset state and count
+			currentState = EParseState::NONE;
+			totalCount = 0;
+			continue;
+		}
+
+		// Process data based on the current state
+		switch (currentState)
+		{
+		case EParseState::NODES:
+			if (aOnNodeRead)
+			{
+				if (!aOnNodeRead(currentIndex, totalCount, line))
+				{
+					keepReading = false;
+				}
+				currentIndex++;
+			}
+			break;
+
+		case EParseState::EDGES:
+		{
+			std::istringstream edgeStream(line);
+			std::string fromNode, toNode, weightStr;
+
+			if (std::getline(edgeStream, fromNode, ';') &&
+				std::getline(edgeStream, toNode, ';') &&
+				std::getline(edgeStream, weightStr))
+			{
+				try
+				{
+					// Use std::stof (string to float) for weight
+					float weight = std::stof(weightStr);
+					if (aOnEdgeRead)
+					{
+						if (!aOnEdgeRead(currentIndex, totalCount, fromNode, toNode, weight))
+						{
+							keepReading = false;
+						}
+						currentIndex++;
+					}
+				}
+				catch (const std::exception&)
+				{
+					// Failed to parse float, skip this line
+				}
+			}
+			break;
+		}
+		case EParseState::NONE:
+		default:
+			break;
+		}
+	}
+	file.close();
+}