1 files changed, 63 insertions, 0 deletions

diff --git a/2023/12/12a.c b/2023/12/12a.c
new file mode 100644
index 0000000..d88ed9a
--- /dev/null
+++ b/2023/12/12a.c
@@ -0,0 +1,63 @@
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define N 1000
+
+#define MAX(a,b) ((a)>(b)?(a):(b))
+#define MIN(a,b) ((a)<(b)?(a):(b))
+#define ABS(a) MAX((a),-(a))
+
+#define isnum(c) (c == '-' || (c >= '0' && c <= '9'))
+
+char *buf, line[N];
+int s, n, a[N];
+
+int readl(int nums[], char *buf) {
+        int64_t i;
+        for (i = 0; *buf; buf++) {
+                if (!isnum(*buf)) continue;
+                nums[i++] = atoll(buf);
+                while (isnum(*buf)) buf++;
+        }
+        return i;
+}
+
+int isgood(char *line, int a[], int n) {
+        int b[N];
+        memset(b, 0, N * sizeof(int));
+        memcpy(b, a, n * sizeof(int));
+        for (int j = 0, c = 0; *line != ' '; line++) {
+                if (*line == '?') printf("Error!\n");
+                if (*line == '.') { j += c; c = 0; }
+                if (*line == '#') { c = 1; b[j]--; }
+        }
+        for (int j = 0; j < N; j++)
+                if (b[j])
+                        return 0;
+        return 1;
+}
+
+int arrange(char *line, char *buf, int a[], int n) {
+        while (*buf != '?' && *buf != ' ') buf++;
+        if (*buf == ' ')
+                return isgood(line, a, n);
+        *buf = '.';
+        int x = arrange(line, buf, a, n);
+        *buf = '#';
+        int y = arrange(line, buf, a, n);
+        *buf = '?';
+        return x + y;
+}
+
+int main() {
+        while ((buf = fgets(line, N, stdin)) != NULL) {
+                n = readl(a, buf);
+                s += arrange(line, buf, a, n);
+        }
+
+        printf("%d\n", s);
+        return 0;
+}