add aoc 2022

1 files changed, 101 insertions, 0 deletions

diff --git a/advent-of-code/2022/07/1.c b/advent-of-code/2022/07/1.c
new file mode 100644
index 0000000..40f96a3
--- /dev/null
+++ b/advent-of-code/2022/07/1.c
@@ -0,0 +1,101 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct dir Dir;
+
+#define LOG(s) fprintf(stderr, s"\n");
+
+struct dir {
+    char name[32];
+    Dir *parent;
+    Dir *next_sibling;
+    Dir *child;
+    int size;
+};
+
+char buf[4096];
+
+Dir root = {0};
+
+int sum = 0;
+
+int totalsize(Dir *dir) {
+    if (dir == NULL) return 0;
+    int total = dir->size;
+    Dir *child = dir->child;
+    while (child != NULL) {
+        total += totalsize(child);
+        child = child->next_sibling;
+    }
+    if (total <= 100000) sum += total;
+    return total;
+}
+
+void process_ls(FILE* fp, Dir *cur) {
+    while (1) {
+        int c = fgetc(fp);
+        if (c == EOF) return;
+        ungetc(c, fp);
+        if (c == '$') {
+            return;
+        }
+        buf[0] = '\0';
+        fgets(buf, 4096, fp);
+        if (buf[0] == 'd') {
+            strtok(buf, " ");
+            char *childname = strtok(NULL, "\n");
+            Dir *newdir = malloc(sizeof(Dir));
+            strcpy(newdir->name, childname);
+            newdir->parent = cur;
+            newdir->next_sibling = cur->child;
+            newdir->child = NULL;
+            newdir->size = 0;
+            cur->child = newdir;
+        } else {
+            char *pos;
+            long fsz = strtol(buf, &pos, 10);
+            cur->size += fsz;
+        }
+    }
+}
+
+void process_cmd(FILE *fp, Dir **pcur) {
+    Dir *cur = *pcur;
+    char *cmd = strtok(buf + 2, " \n"); 
+    if (strcmp(cmd, "cd") == 0) {
+        char *param = strtok(NULL, " \n"); 
+        if (strcmp(param, "/") == 0) {
+            *pcur = &root;
+        } else if (strcmp(param, "..") == 0) {
+            *pcur = cur->parent;
+        } else {
+            Dir *t = cur->child;
+            while (t != NULL) {
+                if (strcmp(t->name, param) == 0) {
+                    *pcur = t;
+                    break;
+                } else {
+                    t = t->next_sibling;
+                }
+            }
+        }
+    } else if (strcmp(cmd, "ls") == 0) {
+        process_ls(fp, cur);
+    }
+}
+
+int main() {
+    FILE *fp = fopen("input", "r");
+    Dir *cur = &root;
+    while (fgets(buf, 4096, fp)) {
+        int len = strlen(buf);
+        if (len <= 1) continue;
+        char c = buf[0];
+        if (c == '$') {
+            process_cmd(fp, &cur);
+        }
+    }
+    totalsize(&root);
+    printf("%d\n", sum);
+}