day 3 part 1 (C) + remove unused-result warning

2021-12-03 21:01:44 +01:00
parent 9a65775f7a
commit edcafd2a00
3 changed files with 150 additions and 0 deletions
--- a/2021/day03/aoc-c.c
+++ b/2021/day03/aoc-c.c
@@ -0,0 +1,107 @@
+/* aoc-c: Advent2021 game, day 2 parts 1 & 2
+ *
+ * Copyright (C) 2021 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.htmlL>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <malloc.h>
+
+#include "debug.h"
+#include "bits.h"
+
+static int ex1()
+{
+    u32 length, gamma = 0, epsilon = 0;
+    char buffer[80];
+    s32 *values;
+
+    /* get length of binary number */
+    scanf("%s", buffer);
+    length = strlen(buffer);
+
+    values = calloc(length, sizeof(*values));
+
+    do {
+        for (u32 i = 0; i < length; ++i) {
+            switch (buffer[i]) {
+                case '0':
+                    values[i]--;
+                    break;
+                case '1':
+                    values[i]++;
+                    break;
+            }
+        }
+    } while (scanf("%s", buffer) != EOF);
+
+    for (u32 i = 0; i < length; ++i) {
+        if (values[i] > 0)
+            gamma += 1 << (length-i-1);
+        else
+            epsilon += 1 << (length-i-1);
+    }
+    free (values);
+    return gamma * epsilon;
+}
+
+static int ex2()
+{
+    /* idea : Given 3 bits input
+     * 101
+     * 010
+     * 110
+     *
+     * we create an ushort array of size 2⁴ initialized at 2⁴
+     *
+     */
+    return 1;
+}
+
+static int usage(char *prg)
+{
+    fprintf(stderr, "Usage: %s [-d debug_level] [-p part]\n", prg);
+    return 1;
+}
+
+int main(int ac, char **av)
+{
+    int opt;
+    u32 exercise = 1, res;
+
+    while ((opt = getopt(ac, av, "d:p:")) != -1) {
+        switch (opt) {
+            case 'd':
+                debug_level_set(atoi(optarg));
+                break;
+            case 'p':                             /* 1 or 2 */
+                exercise = atoi(optarg);
+                break;
+            default:
+                return usage(*av);
+        }
+    }
+
+    if (optind < ac)
+        return usage(*av);
+
+    if (exercise == 1) {
+        res = ex1();
+        printf ("%s : res=%d\n", *av, res);
+    }
+    if (exercise == 2) {
+        res = ex2();
+        printf ("%s : res=%d\n", *av, res);
+    }
+
+    exit (0);
+}