Im trying to write a function that counts the nodes, edges etc. Whenever a node with the same name exists the function shouldn’t count it. The problem is that my function counts some nodes twice. Is there a way to fix it? I tried to use return NULL instead of return node but it gives a memory error.

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "graph.h"

graph_t *init_graph(const char *name) {
    graph_t *graph = calloc(1, sizeof(graph_t));
    if (!graph) {
        fprintf(stderr, "Not enough memory to allocate for graph %sn", name);
        exit(1);
    }
    graph->nodes = NULL;
    graph->count = 0;
    graph->name = calloc(strlen(name) + 1, sizeof(char));
    strcpy(graph->name, name);
    return graph;
}

void free_graph(graph_t *graph) {
    while (graph->count--) {
        node_t *node = graph->nodes[graph->count];
        if (node->num_edges)
            free(node->out_edges);
        free(node->name);
        free(node);
    }
    free(graph->name);
    free(graph->nodes);
    free(graph);
}

node_t *get_node_from_graph(graph_t *graph, const char *name) {
    // Check if a node with the same name already exists
    for (unsigned i = 0; i < graph->count; i++) {
        node_t *node = graph->nodes[i];
        if (!strcmp(node->name, name)) {
            printf("Node %s already exists.n", name);
            return node; // Return existing node
        }
    }
    printf("Adding new node: %sn", name); // debug
    node_t *node = calloc(1, sizeof(node_t));
    node->out_edges = NULL;
    node->num_edges = 0;
    node->name = calloc(strlen(name) + 1, sizeof(char));
    strcpy(node->name, name);
    graph->nodes = realloc(graph->nodes, (graph->count + 1) * sizeof(node_t *));
    graph->nodes[graph->count++] = node;
    return node;
}

void add_edge_to_node(node_t *source, node_t *target) {
    source->out_edges = realloc(source->out_edges, (source->num_edges + 1) * sizeof(node_t *));
    source->out_edges[source->num_edges++] = target;
}