07: C: Add target size parameters

07/solution.c

@@ -1,20 +1,32 @@
 #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;
-    struct entry **entries;
     size_t n_entries;
+    size_t n_alloc;
+    struct entry **entries;
     struct entry *parent;
 } 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];
     }
 
@@ -22,37 +34,41 @@ entry *findent(entry *e, int isdir, const char *name) {
 }
 
 entry *addent(entry *parent, int isdir, const char *name) {
-    if (parent->n_entries)
-        parent->entries = realloc(parent->entries, ++(parent->n_entries) * sizeof(entry*));
-    else
-        parent->entries = malloc(++(parent->n_entries) * sizeof(entry*));
+    if (parent->n_entries >= parent->n_alloc) {
+        parent->n_alloc += 10;
+        if (parent->n_entries)
+            parent->entries = realloc(parent->entries, parent->n_alloc * sizeof(entry*));
+        else
+            parent->entries = malloc(parent->n_alloc * sizeof(entry*));
+    }
+    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;
 }
 
-int main(void) {
+int main(int argc, char **argv) {
     char l[64];
     entry *root = calloc(1, sizeof(entry));
     root->isdir++;
-    entry *current;
+    entry *current = root;
     size_t S = 0, G = 0, required = 0;
 
     while (fgets(l, 64, stdin)) {
         l[strlen(l) - 1] = '\0';
         if (l[0] == '$') {
-            if (l[2] == 'c')
+            if (l[2] == 'c') {
                 if (l[5] == '/')
                     current = root;
                 else if (l[5] == '.')
                     current = current->parent;
                 else
                     current = findent(current, 1, l + 5);
+            }
         } else if (l[0] == 'd') {
             if (!findent(current, 1, l + 4))
                 addent(current, 1, l + 4);
@@ -68,17 +84,21 @@ int main(void) {
     }
 
     current = root;
-    required = 30000000UL - (70000000UL - root->size);
+    if (argc == 3)
+        required = strtoul(argv[2], NULL, 10) - (strtoul(argv[1], NULL, 10) - root->size);
+    else
+        required = 30000000UL - (70000000UL - root->size);
     do {
         if (current->n_entries) {
             current->n_entries--;
             current = (current->entries++)[0];
         } else {
-            if (current->isdir)
+            if (current->isdir) {
                 if (current->size < 100000)
                     S += current->size;
                 else if (current->size >= required && (current->size < G || !G))
                     G = current->size;
+            }
 
             current = current->parent;
         }