ADDED aoc.c
Index: aoc.c
==================================================================
--- /dev/null
+++ aoc.c
@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "aocutils.h"
+#include "aocdailies.h" // prototypes for all aocYYYYdd functions!
+
+#define MAX_YEAR 2024
+
+int main(int argc, char **argv) {
+ int y = 0, d = 0;
+ char dataname[99];
+ if (argc >= 3) {
+ char *err;
+ y = (int)strtol(argv[1], &err, 10);
+ if (err && *err) y = 0;
+ if (y < 2015) y = 0;
+ if (y > MAX_YEAR) y = 0;
+ d = (int)strtol(argv[2], &err, 10);
+ if (err && *err) d = 0;
+ if (d < 1) d = 0;
+ if (d > 25) d = 0;
+ if (argc >= 4) {
+ sprintf(dataname, "%.98s", argv[3]);
+ } else {
+ sprintf(dataname, ".%04d%02d.txt", y, d);
+ }
+ }
+ if ((y == 0) || (d == 0)) {
+ fprintf(stderr, "syntax: %s yyyy dd [input-file]\n", argv[0]);
+ fprintf(stderr, " where 2015 <= yyyy <= %d\n", MAX_YEAR);
+ fprintf(stderr, " and 1 <= dd <= 25\n");
+ fprintf(stderr, "if no [input-file] is supplied loads the file .yyyydd.txt\n");
+ exit(EXIT_FAILURE);
+ }
+ // read data from dataname into input
+ char *input = NULL;
+ size_t ilen = slurp(&input, dataname);
+
+ // call the right function
+ void (*p)(char *, size_t) = NULL;
+ switch (y * 100 + d) {
+ default: fprintf(stderr, "no function for year %d and day %d\n", y, d);
+ exit(EXIT_FAILURE);
+ #if 0
+ case 201501: p = aoc201501; break;
+ case 201502: p = aoc201502; break;
+ case 201503: p = aoc201503; break;
+ case 201504: p = aoc201504; break;
+ case 201505: p = aoc201505; break;
+ case 201506: p = aoc201506; break;
+ case 201507: p = aoc201507; break;
+ case 201508: p = aoc201508; break;
+ case 201509: p = aoc201509; break;
+ case 201510: p = aoc201510; break;
+ case 201511: p = aoc201511; break;
+ case 201512: p = aoc201512; break;
+ case 201513: p = aoc201513; break;
+ case 201514: p = aoc201514; break;
+ case 201515: p = aoc201515; break;
+ case 201516: p = aoc201516; break;
+ case 201517: p = aoc201517; break;
+ case 201518: p = aoc201518; break;
+ case 201519: p = aoc201519; break;
+ case 201520: p = aoc201520; break;
+ case 201521: p = aoc201521; break;
+ case 201522: p = aoc201522; break;
+ case 201523: p = aoc201523; break;
+ case 201524: p = aoc201524; break;
+ case 201525: p = aoc201525; break;
+ #endif
+
+ case 202401: p = aoc202401; break;
+ case 202402: p = aoc202402; break;
+ }
+ p(input, ilen);
+ free(input);
+}
ADDED aoc2024.c
Index: aoc2024.c
==================================================================
--- /dev/null
+++ aoc2024.c
@@ -0,0 +1,113 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "aocutils.h"
+
+static int safereport(int *v, int nv) {
+ int dir = 1; // ascending
+ if (v[0] > v[1]) dir = -1; // descending
+ for (int k = 1; k < nv; k++) {
+ if (v[k-1] == v[k]) return 0;
+ if (abs(v[k-1] - v[k]) > 3) return 0;
+ if (dir == -1) {
+ if (v[k-1] < v[k]) return 0;
+ } else {
+ if (v[k-1] > v[k]) return 0;
+ }
+ }
+ return 1;
+}
+
+static int safereportdamp(int *v, int nv) {
+ for (int swap = 0; swap < nv; swap++) { // abcde
+ int tmp = v[swap]; // swap(0, 0): a-bcde
+ v[swap] = v[0]; // swap(1, 0): b-acde
+ v[0] = tmp; // swap(2, 0): c-abde
+ if (safereport(v + 1, nv - 1)) return 1; // swap(3, 0): d-abce
+ } // ... and so on
+ return 0;
+}
+
+void aoc202402(char *data, [[maybe_unused]] size_t len) {
+ int safe = 0, safe2 = 0;
+ char *line = strtok(data, "\n");
+ while (line) {
+ int *arr = NULL;
+ int narr = text2array(&arr, line);
+ if (safereport(arr, narr)) {
+ safe += 1;
+ safe2 += 1;
+ } else {
+ safe2 += safereportdamp(arr, narr);
+ }
+ free(arr);
+ line = strtok(NULL, "\n");
+ }
+ printf("There are %d safe reports.\n", safe);
+ printf("There are %d safe reports with the Problem Dampener.\n", safe2);
+}
+
+static int delta(const void *a, const void *b) {
+ return *(const int *)a - *(const int *)b;
+}
+
+#ifdef LISTSIZE
+# error LISTSIZE already defined
+#endif
+#define LISTSIZE 1200
+void aoc202401(char *data, [[maybe_unused]] size_t len) {
+ int v1, v2; // values from data
+ char *err;
+ int list1[LISTSIZE], list2[LISTSIZE]; // the lists
+ int n1 = 0, n2 = 0;
+ while ((v1 = (int)strtol(data, &err, 10))) { // assume well-formatted data
+ data = err;
+ v2 = (int)strtoul(data, &err, 10);
+ data = err;
+ list1[n1++] = v1; // add v1 to list1
+ list2[n2++] = v2; // add v2 to list2
+ }
+ // redundant check :-)
+ if (n1 != n2) printf("Error: list are not the same size\n");
+
+ // sort the lists
+ qsort(list1, (size_t)n1, sizeof *list1, delta);
+ qsort(list2, (size_t)n2, sizeof *list2, delta);
+
+ // part1
+ int sumdeltas = 0;
+ for (int k = 0; k < n1; k++) {
+ sumdeltas += abs(list1[k] - list2[k]);
+ }
+ printf("Total distance between lists is {%d}.\n", sumdeltas);
+
+ // part2
+ int similarity = 0;
+ for (int k = 0; k < n1; k++) {
+#if 1 // use the fact lists are sorted: complexity: O(n log n)
+ int leftcount = 1; // number of equal values in list1
+ while ((k + leftcount < n1) && (list1[k] == list1[k + leftcount])) leftcount++;
+ // find list1 k'ths value in list2
+ int *p = bsearch(list1 + k, list2, (size_t)n2, sizeof *list2, delta);
+ if (p) {
+ int idxl = (int)(p - list2); // search backwards and forwards in list2
+ int idxr = (int)(p - list2); // for the k'th value in list1
+ while ((idxl > 0) && (list2[idxl - 1] == *p)) idxl -= 1;
+ while ((idxr < n2 - 1) && (list2[idxr + 1] == *p)) idxr += 1;
+ int rightcount = idxr - idxl + 1; // number of repeats in list2
+ similarity += *p * rightcount * leftcount;
+ }
+ k += leftcount - 1; // adjust loop control variable
+#else
+ // loop inside loop: complexity O(n^2); don't care lists are sorted
+ int count = 0;
+ for (int kk = 0; kk < n2; kk++) {
+ if (list1[k] == list2[kk]) count++;
+ }
+ similarity += list1[k] * count;
+#endif
+ }
+ printf("Similarity score between lists is {%d}.\n", similarity);
+}
+#undef LISTSIZE
ADDED aocdailies.h
Index: aocdailies.h
==================================================================
--- /dev/null
+++ aocdailies.h
@@ -0,0 +1,35 @@
+#ifndef AOCDAILY_H_INCLUDED
+#define AOCDAILY_H_INCLUDED
+
+#if 0
+void aoc201501(char *, size_t);
+void aoc201502(char *, size_t);
+void aoc201503(char *, size_t);
+void aoc201504(char *, size_t);
+void aoc201505(char *, size_t);
+void aoc201506(char *, size_t);
+void aoc201507(char *, size_t);
+void aoc201508(char *, size_t);
+void aoc201509(char *, size_t);
+void aoc201510(char *, size_t);
+void aoc201511(char *, size_t);
+void aoc201512(char *, size_t);
+void aoc201513(char *, size_t);
+void aoc201514(char *, size_t);
+void aoc201515(char *, size_t);
+void aoc201516(char *, size_t);
+void aoc201517(char *, size_t);
+void aoc201518(char *, size_t);
+void aoc201519(char *, size_t);
+void aoc201520(char *, size_t);
+void aoc201521(char *, size_t);
+void aoc201522(char *, size_t);
+void aoc201523(char *, size_t);
+void aoc201524(char *, size_t);
+void aoc201525(char *, size_t);
+#endif
+
+void aoc202401(char *, size_t);
+void aoc202402(char *, size_t);
+
+#endif
ADDED aocutils.c
Index: aocutils.c
==================================================================
--- /dev/null
+++ aocutils.c
@@ -0,0 +1,119 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "aocutils.h"
+
+int text2array(int **dst, const char *r) {
+ int *a = malloc(sizeof *a);
+ int na = 0, sa = 1;
+ char *err;
+ int v;
+ for (;;) {
+ if (na == sa) {
+ int *tmp = realloc(a, (size_t)(2*sa)*sizeof *tmp);
+ if (!tmp) exit(EXIT_FAILURE);
+ a = tmp;
+ sa *= 2;
+ }
+ v = (int)strtol(r, &err, 10);
+ a[na++] = v;
+ if (!*err) break;
+ r = err;
+ }
+ *dst = a;
+ return na;
+}
+
+size_t slurp(char **dst, const char *fn) {
+ if (*dst) {
+ fprintf(stderr, "slurp() must be called with a pointer to void!\n");
+ exit(EXIT_FAILURE);
+ }
+ FILE *h = fopen(fn, "r");
+ if (!h) {
+ perror(fn);
+ exit(EXIT_FAILURE);
+ }
+
+ int ch;
+ char *tmp = malloc(512);
+ size_t s = 512;
+ size_t r = 0;
+ while ((ch = fgetc(h)) != EOF) {
+ if (r == s) {
+ //grow tmp
+ char *ttmp = realloc(tmp, (13*s)/8);
+ if (ttmp) {
+ tmp = ttmp;
+ s = (13*s)/8;
+ } else {
+ free(tmp);
+ return 0;
+ }
+ }
+ tmp[r++] = (char)ch;
+ }
+ fclose(h);
+ *dst = tmp;
+
+ return r;
+}
+
+int max3(int a, int b, int c) {
+ if (a > b) {
+ if (a > c) return a;
+ return c;
+ } else {
+ if (b > c) return b;
+ }
+ return c;
+}
+
+double fmax3(double a, double b, double c) {
+ if (a > b) {
+ if (a > c) return a;
+ return c;
+ } else {
+ if (b > c) return b;
+ }
+ return c;
+}
+
+long max3l(long a, long b, long c) {
+ if (a > b) {
+ if (a > c) return a;
+ return c;
+ } else {
+ if (b > c) return b;
+ }
+ return c;
+}
+
+int min3(int a, int b, int c) {
+ if (a < b) {
+ if (a < c) return a;
+ return c;
+ } else {
+ if (b < c) return b;
+ }
+ return c;
+}
+
+double fmin3(double a, double b, double c) {
+ if (a < b) {
+ if (a < c) return a;
+ return c;
+ } else {
+ if (b < c) return b;
+ }
+ return c;
+}
+
+long min3l(long a, long b, long c) {
+ if (a < b) {
+ if (a < c) return a;
+ return c;
+ } else {
+ if (b < c) return b;
+ }
+ return c;
+}
ADDED aocutils.h
Index: aocutils.h
==================================================================
--- /dev/null
+++ aocutils.h
@@ -0,0 +1,13 @@
+#ifndef AOCUTILS_H_INCLUDED
+#define AOCUTILS_H_INCLUDED
+
+int text2array(int **dst, const char *r);
+size_t slurp(char **dst, const char *filename);
+int max3(int a, int b, int c);
+double fmax3(double a, double b, double c);
+long max3l(long a, long b, long c);
+int min3(int a, int b, int c);
+double fmin3(double a, double b, double c);
+long min3l(long a, long b, long c);
+
+#endif