Index: aoc2024.c
==================================================================
--- aoc2024.c
+++ aoc2024.c
@@ -6,10 +6,14 @@
 #include <string.h>
 #include "aocdailies.h"
 #include "aocutils.h"
 
 static void reorder(unsigned *a, size_t na, unsigned (*r)[2], size_t nr) {
+    (void)a;
+    (void)na;
+    (void)r;
+    (void)nr;
 }
 
 static const unsigned *vfind(unsigned v, const unsigned *a, size_t n) {
     for (size_t k = 0; k < n; k++) {
         if (a[k] == v) return a + k;
@@ -18,31 +22,39 @@
 }
 
 void aoc202405(char *data, size_t len) {
     (void)len; // unused argument
     unsigned pagepair[1200][2], npp = 0; // 1200 works for me
+    unsigned ppcount[100][2] = {0}; // assume all page numbers < 100
     char *line = strtok(data, "\n");
     while (strchr(line, '|')) {
         char *err;
         pagepair[npp][0] = strtoul(line, &err, 10);
+        ppcount[pagepair[npp][0]][0]++;
         err += 1; // skip '|'
         pagepair[npp][1] = strtoul(err, &err, 10);
+        ppcount[pagepair[npp][1]][1]++;
         npp++;
         line = strtok(NULL, "\n");
     }
+    for (unsigned k = 0; k < 100; k++) {
+        if (ppcount[k][0] + ppcount[k][1])
+              printf("%u: [%u, %u]  ", k, ppcount[k][0], ppcount[k][1]);
+    }
+    printf("\n");
     unsigned update[32], nupdates; // 32 works for me
-    unsigned accumsum = 0;
+    unsigned accumsum = 0, accumsum2 = 0;
     do {
         nupdates = 0;
         char *err = line;
         for (;;) {
             update[nupdates++] = strtoul(err, &err, 10);
             if (*err == ',') err++;
             else break;
         }
         if (nupdates % 2 == 0) printf("even number of updates found!\n");
-        unsigned accum = update[nupdates / 2], accumsum2 = 0;
+        unsigned accum = update[nupdates / 2];
         for (size_t k = 0; k < npp; k++) {
             const unsigned *before = vfind(pagepair[k][0], update, nupdates);
             if (!before) continue;
             const unsigned *after = vfind(pagepair[k][1], update, nupdates);
             if (!after) continue;