A few bug fixes in graph.c

1 files changed, 6 insertions, 3 deletions

diff --git a/src/graph.c b/src/graph.c
index f3e7517..cd2d796 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -18,8 +18,8 @@ Graph *graph_new(int n) {
         return NULL;
     }
 
-    graph->num_edges = n;
-    graph->num_vertices = 0;
+    graph->num_edges = 0;
+    graph->num_vertices = n;
     
     for (int i = 0; i < n; i++) {
         graph->vertices[i].id = i;
@@ -57,6 +57,9 @@ void graph_remove_edge(Graph *g, int i, int j) {
 
 Graph *graph_read(const char *filename) {
     FILE *file = fopen(filename, "r");
+    if (!file)
+        return NULL;
+
     char line[1024];
     fgets(line, 1024, file);
 
@@ -66,7 +69,7 @@ Graph *graph_read(const char *filename) {
     Graph *g = graph_new(n);
 
     char c = line[0];
-    int i, j = 0;
+    int i = 0, j = 0;
     while (fgets(line, 1024, file)) {
         while (c != '\n') {
             if (c == '1') {