Added solutions for 21 and 22

1 files changed, 77 insertions, 0 deletions

diff --git a/2023/22/22a.c b/2023/22/22a.c
new file mode 100644
index 0000000..a70a181
--- /dev/null
+++ b/2023/22/22a.c
@@ -0,0 +1,77 @@
+#include <inttypes.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define N 1500
+#define M 340
+#define MAX(x,y) ((x)>(y)?(x):(y))
+
+#define isnum(c) (c == '-' || (c >= '0' && c <= '9'))
+
+char line[N];
+int n, x, b[N][6], cube[M][M][M];
+
+void readl(int nums[], char *buf) {
+        for (int i = 0; i < 6; i++) {
+                nums[i] = atoi(buf);
+                while (isnum(*buf)) buf++;
+                buf++;
+        }
+}
+
+bool droppable(int i) {
+        int z = b[i][2];
+        if (z == 1) return false;
+        for (int x = b[i][0]; x <= b[i][3]; x++)
+                for (int y = b[i][1]; y <= b[i][4]; y++)
+                        if (cube[x][y][z-1])
+                                return false;
+        return true;
+}
+
+void set(int n, int c) {
+        for (int i = b[n][0]; i <= b[n][3]; i++)
+                for (int j = b[n][1]; j <= b[n][4]; j++)
+                        for (int k = b[n][2]; k <= b[n][5]; k++)
+                                cube[i][j][k] = c;
+}
+
+void dobreak(int n) { set(n, 0); }
+void unbreak(int n) { set(n, n+1); }
+
+void drop(int i) {
+        dobreak(i);
+        b[i][2]--;
+        b[i][5]--;
+        unbreak(i);
+}
+
+int disintegratable(int i) {
+        int ret = 1;
+        dobreak(i);
+        for (int j = 0; j < n; j++)
+                if (j != i && droppable(j))
+                        ret = 0;
+        unbreak(i);
+        return ret;
+}
+
+int main() {
+        for (n = 0; fgets(line, N, stdin) != NULL; n++) {
+                readl(b[n], line);
+                unbreak(n);
+        }
+
+        for (int i = 0; i < N; i++)
+                for (int j = 0; j < n; j++)
+                        while (droppable(j))
+                                drop(j);
+
+        for (int i = 0; i < n; i++)
+                x += disintegratable(i);
+
+        printf("%d\n", x);
+        return 0;
+}