diff --git a/07/solution.c b/07/solution.c
index 2adade7..323d35d 100644
--- a/07/solution.c
+++ b/07/solution.c
@@ -1,9 +1,19 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdint.h>
+
+uint32_t fnv1a_32(const char *buf, size_t len)
+{
+    uint32_t h = 0x811c9dc5U;
+    for (; len > 0; len--)
+        h = 0x01000193U * (h ^ *buf++);
+
+    return h;
+}
 
 typedef struct entry {
-    char *name;
+    uint32_t id;
     int isdir;
     size_t size;
     size_t n_entries;
@@ -13,9 +23,10 @@ typedef struct entry {
 } entry;
 
 entry *findent(entry *e, int isdir, const char *name) {
+    uint32_t id = fnv1a_32(name, strlen(name));
     for (size_t i = 0; i < e->n_entries; i++) {
         if (e->entries[i]->isdir == isdir)
-            if (!strcmp(e->entries[i]->name, name))
+            if (e->entries[i]->id == id)
                 return e->entries[i];
     }
 
@@ -33,9 +44,8 @@ entry *addent(entry *parent, int isdir, const char *name) {
     parent->n_entries++;
 
     entry *e = parent->entries[parent->n_entries - 1] = calloc(1, sizeof(entry));
+    e->id = fnv1a_32(name, strlen(name));
     e->isdir = isdir;
-    e->name = malloc(strlen(name) + 1);
-    strcpy(e->name, name);
     e->parent = parent;
 
     return e;