Day22 C

day22/c/day22.c

@@ -0,0 +1,140 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <omp.h>
+
+#define LINE_MAX_LENGTH 256
+#define MAX_BRICKS 2048
+#define NUM_0_CHARCODE 48
+#define NUM_9_CHARCODE NUM_0_CHARCODE + 9
+#define max(a,b) ((a) > (b) ? (a) : (b))
+#define min(a,b) ((a) < (b) ? (a) : (b))
+#define in_range(c,a,b) ((c) <= max(a,b) && (c) >= min(a,b))
+
+typedef struct corner {
+    int x;
+    int y;
+    int z;
+} corner_t;
+
+typedef struct brick {
+    corner_t corners[2];
+    int fallen;
+} brick_t;
+
+int fall(brick_t bricks[], int bricks_num);
+int intersect(brick_t brick_a, brick_t brick_b);
+
+int main() {
+    char *p, *buf, c;
+
+    buf = (char *)malloc(LINE_MAX_LENGTH);
+    memset(buf, 0, LINE_MAX_LENGTH);
+    p = buf;
+
+    brick_t bricks[MAX_BRICKS];
+    int bricks_num = 0;
+
+    while ((c = getchar()) != EOF) {
+        *p++ = c;
+        if (c == '\n') {
+            p = buf;
+            sscanf(p, "%i", &bricks[bricks_num].corners[0].x);
+            while (*p != ',') p++;
+            p++;
+            sscanf(p, "%i", &bricks[bricks_num].corners[0].y);
+            while (*p != ',') p++;
+            p++;
+            sscanf(p, "%i", &bricks[bricks_num].corners[0].z);
+            while (*p != '~') p++;
+            p++;
+            sscanf(p, "%i", &bricks[bricks_num].corners[1].x);
+            while (*p != ',') p++;
+            p++;
+            sscanf(p, "%i", &bricks[bricks_num].corners[1].y);
+            while (*p != ',') p++;
+            p++;
+            sscanf(p, "%i", &bricks[bricks_num].corners[1].z);
+            bricks_num++;
+            memset(buf, 0, LINE_MAX_LENGTH);
+            p = buf;
+        }
+    }
+
+    
+    while (fall(bricks, bricks_num));
+    for (int i = 0; i < bricks_num; i++) {
+        bricks[i].fallen = 0;
+    }
+
+    int part1 = 0;
+    int part2 = 0;
+#pragma omp parallel for schedule(dynamic)
+    for (int i = 0; i < bricks_num; i++) {
+        brick_t bricks_copy[MAX_BRICKS];
+        memcpy(bricks_copy, bricks, sizeof(bricks));
+        bricks_copy[i].corners[0].z = 0;
+        bricks_copy[i].corners[1].z = 0;
+        int fallen = 0;
+        while (fall(bricks_copy, bricks_num));
+        for (int j = 0; j < bricks_num; j++) {
+            fallen += bricks_copy[j].fallen;
+        }
+#pragma omp critical
+        {
+            if (fallen == 0) {
+                part1++;
+            }
+            part2 += fallen;
+        }
+    }
+
+    printf("%i\n", part1);
+    printf("%i\n", part2);
+
+    free(buf);
+}
+
+int fall(brick_t bricks[], int bricks_num) {
+    int result = 0;
+    for (int i = 0; i < bricks_num; i++) {
+        int fallen = 0;
+        for (;;) {
+            bricks[i].corners[0].z--;
+            bricks[i].corners[1].z--;
+            if (bricks[i].corners[0].z <= 0 || bricks[i].corners[1].z <= 0) {
+                break;
+            }
+            int collision = 0;
+            for (int j = 0; j < bricks_num; j++) {
+                if (i == j) continue;
+                if (intersect(bricks[i], bricks[j])) {
+                    collision = 1;
+                    break;
+                }
+            }
+            if (collision) {
+                break;
+            }
+            bricks[i].fallen = 1;
+            fallen = 1;
+        }
+        bricks[i].corners[0].z++;
+        bricks[i].corners[1].z++;
+        result += fallen;
+    }
+    
+    return result;
+}
+
+int intersect(brick_t brick_a, brick_t brick_b) {
+    if (
+        (in_range(brick_b.corners[0].x, brick_a.corners[0].x, brick_a.corners[1].x) || in_range(brick_b.corners[1].x, brick_a.corners[0].x, brick_a.corners[1].x) || in_range(brick_a.corners[1].x, brick_b.corners[0].x, brick_b.corners[1].x) || in_range(brick_a.corners[0].x, brick_b.corners[0].x, brick_b.corners[1].x)) &&
+        (in_range(brick_b.corners[0].y, brick_a.corners[0].y, brick_a.corners[1].y) || in_range(brick_b.corners[1].y, brick_a.corners[0].y, brick_a.corners[1].y) || in_range(brick_a.corners[1].y, brick_b.corners[0].y, brick_b.corners[1].y) || in_range(brick_a.corners[0].y, brick_b.corners[0].y, brick_b.corners[1].y)) &&
+        (in_range(brick_b.corners[0].z, brick_a.corners[0].z, brick_a.corners[1].z) || in_range(brick_b.corners[1].z, brick_a.corners[0].z, brick_a.corners[1].z) || in_range(brick_a.corners[1].z, brick_b.corners[0].z, brick_b.corners[1].z) || in_range(brick_a.corners[0].z, brick_b.corners[0].z, brick_b.corners[1].z))
+    ) {
+        return 1;
+    }
+
+    return 0;
+}

day22/sample.txt

@@ -0,0 +1,7 @@
+1,0,1~1,2,1
+0,0,2~2,0,2
+0,2,3~2,2,3
+0,0,4~0,2,4
+2,0,5~2,2,5
+0,1,6~2,1,6
+1,1,8~1,1,9