advent2025

commit 7fd372e83bd54861fc4e26e8cc1ebba8b9f427ba
parent b609d1484f17b56f2fb95e74019e25be48948f9c
Author: bsandro <email@bsandro.tech>
Date:   Thu, 11 Dec 2025 09:01:14 +0200

day11 p1

Diffstat:
A
day11.c
 | 
94
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 94 insertions(+), 0 deletions(-)
diff --git a/day11.c b/day11.c
@@ -0,0 +1,94 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include "cputime.h"
+
+#define NAME_LEN 4
+#define MAX_NODES 600
+
+typedef struct Node {
+    char name[NAME_LEN];
+    int adj_l;
+    struct Node *adj[32];
+} Node;
+
+typedef struct {
+    Node nodes[MAX_NODES];
+    int cnt;
+} Nodes;
+
+Node * find(Nodes *nodes, char name[4]) {
+    Node *n = NULL;
+    for (int i=0;i<nodes->cnt;++i) {
+        if (strncmp(name, nodes->nodes[i].name, NAME_LEN-1)==0) {
+            return &nodes->nodes[i];
+        }
+    }
+    return n;
+}
+
+Node * find_or_create(Nodes *nodes, char name[4]) {
+    Node *n = find(nodes, name);
+    if (n!=NULL) return n;
+    n = &nodes->nodes[nodes->cnt++];
+    strcpy(n->name, name);
+    return n;
+}
+
+int bfs1(Nodes *nodes) {
+    int num = 0;
+    Node *start = find(nodes, "you");
+    Node *end = find(nodes, "out");
+    Node *queue[MAX_NODES] = {0};
+    int front = 0;
+    int back = 0;
+    queue[back++] = start;
+    while (front<back) {
+        Node *cur = queue[front++];
+        if (cur==end) num++;
+        for (int i=0;i<cur->adj_l;++i) {
+            queue[back++] = cur->adj[i];
+        }
+    }
+    return num;
+}
+
+int bfs2(Nodes *nodes) {
+    int num = 0;
+    Node *start = find(nodes, "you");
+    Node *end = find(nodes, "out");
+    Node *queue[MAX_NODES] = {0};
+    int front = 0;
+    int back = 0;
+    queue[back++] = start;
+    while (front<back) {
+        Node *cur = queue[front++];
+        if (cur==end) num++;
+        for (int i=0;i<cur->adj_l;++i) {
+            queue[back++] = cur->adj[i];
+        }
+    }
+    return num;
+}
+
+int main(void) {
+    char buf[NAME_LEN];
+    int buf_l = 0;
+    Nodes nodes = {0};
+    Node *node = NULL;
+    for (int c=getchar();c!=EOF;c=getchar()) {
+        if (c>='a'&&c<='z') buf[buf_l++] = c;
+        else if (c==':') {
+            node = find_or_create(&nodes, buf);
+            buf_l = 0;
+        } else if (c=='\n'||(c==' '&&buf_l>0)) {
+            node->adj[node->adj_l++] = find_or_create(&nodes, buf);
+            buf_l = 0;
+            if (c=='\n') node = NULL;
+        }
+    }
+
+    int p1 = bfs1(&nodes);
+    printf("p1: %d\n", p1);
+    return 0;
+}