Graph

Graph/c_GraphDFS.c

@@ -0,0 +1,63 @@
+#include <c_GraphDFS.h>
+
+// Internal recursive helper function that tracks execution states down the stack frames
+static c_bool_t c_Graph_DFS_Internal(
+    const c_Graph_t* self,
+    c_size_t current_vertex,
+    c_bool_t* visited,
+    c_Graph_DFS_Callback callback,
+    void* context)
+{
+    // Mark node as discovered
+    visited[current_vertex] = C_TRUE;
+
+    // Execute user callback function. If it returns false, bubble up to trigger an early abort.
+    if (callback && !callback(current_vertex, context)) {
+        return C_FALSE;
+    }
+
+    const c_AdjList_t* neighbors = &self->adj_list[current_vertex];
+
+    // Cache-friendly sequential scan over the contiguous array of primitive integer neighbors
+    for (c_size_t i = 0; i < neighbors->size; i++) {
+        c_uint_t neighbor = neighbors->array[i];
+
+        if (!visited[neighbor]) {
+            // Recurse into unvisited neighbors. Propagate abort commands immediately.
+            if (!c_Graph_DFS_Internal(self, neighbor, visited, callback, context)) {
+                return C_FALSE;
+            }
+        }
+    }
+
+    return C_TRUE; // Continue searching normally
+}
+
+c_err_t c_Graph_DFS(const c_Graph_t* self, c_size_t src_vertex, c_Graph_DFS_Callback callback, void* context, c_Allocator_t* allocator) {
+    if (!self || src_vertex >= self->V) {
+        return C_ERR_PARAM;
+    }
+
+    if (self->V == 0) {
+        return C_SUCCESS;
+    }
+
+    allocator = allocator?allocator:&c_DefaultAllocator;
+
+    // Allocate tracking memory via the graph's configured allocator
+    c_bool_t* visited = (c_bool_t*)c_Allocator_Alloc(allocator, self->V * sizeof(c_bool_t));
+    if (!visited) {
+        return C_ERR_NOMEM;
+    }
+
+    // Initialize all tracking slots to false
+    memset(visited, 0, self->V * sizeof(c_bool_t));
+
+    // Launch the deep structural recursive traversal engine
+    c_Graph_DFS_Internal(self, src_vertex, visited, callback, context);
+
+    // Safely free the temporary visited array tracking memory bounds
+    c_Allocator_Free(allocator, visited);
+
+    return C_SUCCESS;
+}