advent2025

commit 164d5e2fa652b528c8f0de1b41f4520a80bf620b
parent 9e218d4783dc432e405a84c993f919178022bbe2
Author: bsandro <email@bsandro.tech>
Date:   Thu, 11 Dec 2025 22:39:43 +0200

day11 p2 still does not work but I feel I am close

Diffstat:
M
Makefile
 | 
3
+++
M
day11.c
 | 
46
++++++++++++++++++++++++++--------------------

2 files changed, 29 insertions(+), 20 deletions(-)
diff --git a/Makefile b/Makefile
@@ -36,6 +36,9 @@ endif
 %+test: %.bin
 	./$< < inputs/$*_test.txt
 
+%+test1: %.bin
+	./$< < inputs/$*_test1.txt
+
 .SECONDARY:
 %: %.bin
 	@:
diff --git a/day11.c b/day11.c
@@ -1,3 +1,9 @@
+/*
+Test input #1 works only with part1 of the puzzle.
+Test input #2 works only with part2 of the puzzle.
+Thing crashes pretty hard if 'svr'/'our' nodes weren't found, I don't care much.
+ */
+
 #include <stdio.h>
 #include <string.h>
 #include <strings.h>
@@ -6,13 +12,14 @@
 #include "cputime.h"
 
 #define NAME_LEN 4
-#define MAX_NODES 100000
+#define MAX_NODES 10000
 
 typedef struct Node {
     char name[NAME_LEN];
     int adj_l;
     int adj[32];
     bool visited;
+    bool dead;
 } Node;
 
 typedef struct {
@@ -60,12 +67,14 @@ int find_or_create(Nodes *nodes, char name[4]) {
 int bfs(Nodes *nodes) {
     int num = 0;
     int start = find_index(nodes, "you");
+    if (start==-1) return -1;
     int end = find_index(nodes, "out");
     int queue[MAX_NODES] = {0};
     int front = 0;
     int back = 0;
     queue[back++] = start;
     while (front<back) {
+        if (front>=MAX_NODES||back>=MAX_NODES) exit(1);
         int cur = queue[front++];
         if (cur==end) num++;
         Node *cur_node = &nodes->nodes[cur];
@@ -76,44 +85,40 @@ int bfs(Nodes *nodes) {
     return num;
 }
 
-int dfs_walk(Nodes *nodes, int idx) {
-    int end = find_index(nodes, "out");
-    int dac = find_index(nodes, "dac");
-    int fft = find_index(nodes, "fft");
-    if (idx==end) {
+int dfs_walk(Nodes *nodes, int idx, int out, int dac, int fft) {
+    if (idx==out) {
+        for (int i=0;i<nodes->cnt;++i) if (nodes->nodes[i].visited) printf("-> %3d ",i);
+        printf("\n");
         if (nodes->nodes[dac].visited&&nodes->nodes[fft].visited) return 1;
         else return 0;
     }
     Node *n = &nodes->nodes[idx];
     n->visited = true;
+    if (n->dead) return 0;
     int num = 0;
     for (int i=0;i<n->adj_l;++i) {
-        num += dfs_walk(nodes, 0);
+        if (nodes->nodes[n->adj[i]].visited) continue;
+        //if (nodes->nodes[n->adj[i]].dead) continue;
+        num += dfs_walk(nodes, n->adj[i], out, dac, fft);
     }
     n->visited = false;
+    if (num==0) n->dead = true;
     return num;
 }
 
 int dfs(Nodes *nodes) {
     int num = 0;
+    int out = find_index(nodes, "out");
+    int dac = find_index(nodes, "dac");
+    int fft = find_index(nodes, "fft");
     Node *start = find(nodes, "svr");
+    if (start==NULL) return -1;
     for (int i=0;i<start->adj_l;++i) {
-        num += dfs_walk(nodes, start->adj[i]);
+        num += dfs_walk(nodes, start->adj[i], out, dac, fft);
     }
     return num;
 }
 
-void print_nodes(Nodes *nodes) {
-    printf("%d nodes\n", nodes->cnt);
-    for (int i=0;i<nodes->cnt;++i) {
-        printf("(%d) [%s] -> ", i, nodes->nodes[i].name);
-        for (int j=0;j<nodes->nodes[i].adj_l;++j) {
-            printf("[%d:%s]", nodes->nodes[i].adj[j], nodes->nodes[nodes->nodes[i].adj[j]].name);
-        }
-        printf("\n");
-    }
-}
-
 int main(void) {
     char buf[NAME_LEN];
     int buf_l = 0;
@@ -133,7 +138,8 @@ int main(void) {
     }
 
     int p1 = bfs(nodes);
-    int p2 = 0;//dfs(nodes);
+    int p2 = dfs(nodes);
     printf("p1: %d\np2: %d\n", p1, p2);
     return 0;
 }
+// 18