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Check-in [88be09eaef]

Overview
Comment:202405 -- structure for part 2 in place; time for a think
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SHA3-256: 88be09eaef3f57549a975df604d531ce1aedb0f4d8aa7cef986310766c026ceb
User & Date: nnz on 2024-12-05 12:32:29
Other Links: manifest | tags
Context
2024-12-05
14:39
202405 -- new idea: count pages positions check-in: fccbd87615 user: nnz tags: trunk
12:32
202405 -- structure for part 2 in place; time for a think check-in: 88be09eaef user: nnz tags: trunk
12:15
202405 1st star check-in: a12cf534f9 user: nnz tags: trunk
Changes
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Modified aoc2024.c from [6e28b1efce] to [f1c77ad8a8]. 

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#include <ctype.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "aocdailies.h"
#include "aocutils.h"

static void reorder(unsigned *a, size_t na, unsigned (*r)[2], size_t 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;
    }
    return NULL;
}
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        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 accumulate = update[nupdates / 2];
        unsigned accum = update[nupdates / 2], accumsum2 = 0;
        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;
            if (before > after) { accumulate = 0; break; }
        }
        accumsum += accumulate;
            if (before > after) {
                accum = 0;
                // reorder `update` according to `pagepair`
                reorder(update, nupdates, pagepair, npp);
                accumsum2 += update[nupdates / 2];
                break;
            }
        }
        accumsum += accum;
    } while ((line = strtok(NULL, "\n")) != NULL);
    printf("The sum of middle update numbers is {%u}\n", accumsum);
    printf("The sum of middle update numbers for newly ordered updates is {%u}\n", accumsum2);
}

static size_t rcmap(unsigned size, unsigned row, unsigned col) {
    return row * (size + 1) + col;
}

static bool masat(char *data, unsigned size, unsigned row, unsigned col, int drow, int dcol) {
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