Week 151: C solutions

2 files changed, 158 insertions, 0 deletions

diff --git a/challenge-151/abigail/c/ch-1.c b/challenge-151/abigail/c/ch-1.c
new file mode 100644
index 0000000000..e4487ddaec
--- /dev/null
+++ b/challenge-151/abigail/c/ch-1.c
@@ -0,0 +1,96 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+# include <stdbool.h>
+# include <ctype.h>
+
+/*
+ * See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+ */
+
+/*
+ * Run as: cc -o ch-1.o ch-1.c; ./ch-1.o < input-file
+ */
+
+int main (void) {
+    char *  line    = NULL;
+    size_t  len     = 0;
+    size_t  str_len;
+
+    while ((str_len = getline (&line, &len, stdin)) != -1) {
+        char * line_ptr = line;
+        /*
+         * Count the number of '|' characters; this determines
+         * how many elements to allocate for our tree.
+         */
+        int size = 3;
+        while (* line_ptr) {
+            if (* line_ptr ++ == '|') {
+                size = 2 * size + 1;
+            }
+        }
+        bool * tree;
+        if ((tree = (bool *) malloc (size * sizeof (bool))) == NULL) {
+            perror ("Malloc tree failed");
+            exit (1);
+        }
+        for (size_t i = 0; i < size; i ++) {
+            tree [i] = false;
+        }
+
+        int D = 0;
+        int i = 0;
+        size_t offset = 0;
+        line_ptr = line;
+        /*
+         * Skip leading spaces
+         */
+        while (* line_ptr && isspace (* line_ptr)) {
+            line_ptr ++;
+        }
+        while (* line_ptr) {
+            if (* line_ptr == '|') {
+                D ++;
+                i = 0;
+                offset = 2 * offset + 1;
+                line_ptr ++;
+                continue;
+            }
+            if (* line_ptr == '*') {
+                i ++;
+                line_ptr ++;
+                continue;
+            }
+            if (isspace (* line_ptr)) {
+                while (* line_ptr && isspace (* line_ptr)) {
+                    line_ptr ++;
+                }
+                continue;
+            }
+            tree [offset + i] = true;
+            i ++;
+            while (* line_ptr && !isspace (* line_ptr) && * line_ptr != '|') {
+                line_ptr ++;
+            }
+        }
+
+        int width = 1;
+        int k     = 0;
+        bool done = false;
+        for (int d = 0; d <= D && !done; d ++) {
+            for (int i = 0; i < width && !done; i ++) {
+                if (tree [k] && !tree [2 * k + 1] && !tree [2 * k + 2]) {
+                    printf ("%d\n", d + 1);
+                    done = true;
+                }
+                k ++;
+            }
+            width *= 2;
+        }
+
+        free (tree);
+    }
+    free (line);
+
+    return (0);
+}
diff --git a/challenge-151/abigail/c/ch-2.c b/challenge-151/abigail/c/ch-2.c
new file mode 100644
index 0000000000..c2a62f6c92
--- /dev/null
+++ b/challenge-151/abigail/c/ch-2.c
@@ -0,0 +1,62 @@
+# include <stdlib.h>
+# include <stdio.h>
+# include <string.h>
+
+/*
+ * See https://theweeklychallenge.org/blog/perl-weekly-challenge-151
+ */
+
+/*
+ * Run as: cc -o ch-2.o ch-2.c; ./ch-2.o < input-file
+ */
+
+int max (int a, int b) {
+    return a < b ? b : a;
+}
+
+int main (void) {
+    char *  line    = NULL;
+    size_t  len     = 0;
+    size_t  str_len;
+
+    while ((str_len = getline (&line, &len, stdin)) != -1) {
+        char * line_ptr = line;
+        int * houses = NULL;
+        int * best   = NULL;
+        int val;
+        int offset;
+        int nr_of_houses = 0;
+
+        while (sscanf (line_ptr, "%d%n", &val, &offset) == 1) {
+            if ((houses = (int *)
+                 realloc (houses, ++ nr_of_houses * sizeof (int))) == NULL) {
+                perror ("Recalloc failed");
+                exit (1);
+            }
+            houses [nr_of_houses - 1] = val;
+            line_ptr += offset;
+        }
+
+        if ((best = (int *) malloc (nr_of_houses * sizeof (int))) == NULL) {
+            perror ("Malloc failed");
+            exit (1);
+        }
+
+        for (int i = nr_of_houses - 1; i >= 0; i --) {
+            best [i] = nr_of_houses < 2      ? houses [i]
+                     : i == nr_of_houses - 1 ? houses [i]
+                     : i == 0                ? houses [i]      + best [i + 2]
+                     : i == nr_of_houses - 2 ? max (houses [i],  best [i + 1])
+                     :                         max (houses [i] + best [i + 2],
+                                                                 best [i + 1]);
+        }
+
+        printf ("%d\n", best [0]);
+
+        free (houses);
+        free (best);
+    }
+    free (line);
+
+    return (0);
+}