Initial

.gitignore

@@ -0,0 +1,6 @@
+*.tar.gz
+build
+release
+docs
+zig-out
+zig-cache

Makefile

@@ -0,0 +1,59 @@
+BIN := graphs
+# Compiler
+CC := gcc
+
+GITHASH := $(shell git rev-parse --short HEAD)
+
+# Compiler flags
+CFLAGS := -Wall -Wextra -Wpedantic -std=c2x
+
+# Directories
+SRC_DIR := src
+BUILD_DIR := build
+
+# Source files
+SRCS := $(wildcard $(SRC_DIR)/*.c)
+
+# Header files (used for formatting)
+HEADERS := $(wildcard $(SRC_DIR)/*.h)
+
+# Object files
+OBJS := $(patsubst $(SRC_DIR)/%.c,$(BUILD_DIR)/%.o,$(SRCS))
+
+# Target executable
+TARGET := $(BUILD_DIR)/$(BIN)
+
+# Default target
+all: $(TARGET)
+
+# Rule to build the target executable
+$(TARGET): $(OBJS)
+	$(CC) $(CFLAGS) $^ -o $@
+
+# Rule to build object files
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.c
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+# Run rule
+run: $(TARGET)
+	./$(TARGET)
+
+fmt:
+	clang-format -i $(SRCS) $(HEADERS)
+
+# Clean rule
+clean:
+	rm -rf $(BUILD_DIR) $(TARGET)
+
+docs:
+	PROJECT_NUMBER=git-$(GITHASH) doxygen Doxyfile
+
+cppcheck:
+	cppcheck --enable=all --inconclusive --std=c11 --language=c --platform=unix64 --suppress=missingIncludeSystem $(SRCS)
+
+valgrind: $(TARGET)
+	valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes ./$(TARGET)
+
+# Mark rules as phony
+.PHONY: all run clean docs docs

src/main.c

@@ -0,0 +1,104 @@
+// DFS algorithm in C
+
+#include <stdio.h>
+#include <stdlib.h>
+
+struct node {
+  int vertex;
+  struct node* next;
+};
+
+struct node* createNode(int v);
+
+struct Graph {
+  int numVertices;
+  int* visited;
+
+  // We need int** to store a two dimensional array.
+  // Similary, we need struct node** to store an array of Linked lists
+  struct node** adjLists;
+};
+
+// DFS algo
+void DFS(struct Graph* graph, int vertex) {
+  struct node* adjList = graph->adjLists[vertex];
+  struct node* temp = adjList;
+
+  graph->visited[vertex] = 1;
+  printf("Visited %d \n", vertex);
+
+  while (temp != NULL) {
+    int connectedVertex = temp->vertex;
+
+    if (graph->visited[connectedVertex] == 0) {
+      DFS(graph, connectedVertex);
+    }
+    temp = temp->next;
+  }
+}
+
+// Create a node
+struct node* createNode(int v) {
+  struct node* newNode = malloc(sizeof(struct node));
+  newNode->vertex = v;
+  newNode->next = NULL;
+  return newNode;
+}
+
+// Create graph
+struct Graph* createGraph(int vertices) {
+  struct Graph* graph = malloc(sizeof(struct Graph));
+  graph->numVertices = vertices;
+
+  graph->adjLists = malloc(vertices * sizeof(struct node*));
+
+  graph->visited = malloc(vertices * sizeof(int));
+
+  int i;
+  for (i = 0; i < vertices; i++) {
+    graph->adjLists[i] = NULL;
+    graph->visited[i] = 0;
+  }
+  return graph;
+}
+
+// Add edge
+void addEdge(struct Graph* graph, int src, int dest) {
+  // Add edge from src to dest
+  struct node* newNode = createNode(dest);
+  newNode->next = graph->adjLists[src];
+  graph->adjLists[src] = newNode;
+
+  // Add edge from dest to src
+  newNode = createNode(src);
+  newNode->next = graph->adjLists[dest];
+  graph->adjLists[dest] = newNode;
+}
+
+// Print the graph
+void printGraph(struct Graph* graph) {
+  int v;
+  for (v = 0; v < graph->numVertices; v++) {
+    struct node* temp = graph->adjLists[v];
+    printf("\n Adjacency list of vertex %d\n ", v);
+    while (temp) {
+      printf("%d -> ", temp->vertex);
+      temp = temp->next;
+    }
+    printf("\n");
+  }
+}
+
+int main() {
+  struct Graph* graph = createGraph(4);
+  addEdge(graph, 0, 1);
+  addEdge(graph, 0, 2);
+  addEdge(graph, 1, 2);
+  addEdge(graph, 2, 3);
+
+  printGraph(graph);
+
+  DFS(graph, 2);
+
+  return 0;
+}