2022 day22 part1

1 files changed, 44 insertions, 51 deletions

diff --git a/src/2022/day22/aoc.cpp b/src/2022/day22/aoc.cpp
index 305d5f2..6133492 100644
--- a/src/2022/day22/aoc.cpp
+++ b/src/2022/day22/aoc.cpp
@@ -11,73 +11,64 @@ struct person {
   facing f;
 };
 
-int get_x(int x, const monkey_map& r0, const monkey_map& r1) {
-  int s0 = r0.start + r0.line.length;
-  int s1 = r1.start + r1.line.length;
-
-  if (s0 < s1 && r0.start + x >= r1.start) {
-    return r0.start + x - r1.start;
-  }
-  if (s0 > s1 && r0.start + x < s1) {
-    return r0.start + x - r1.start;
-  }
-  return x;
+static int absolute_x(int x, const monkey_map& r) {
+  return r.start + x;
 }
 
-int find_last(int y, const std::vector<monkey_map>& ms) {
-  const monkey_map& r = ms[y];
-  int n = y;
-  while (n < (int)ms.size() && ms[n].start + ms[n].line.length == r.start + r.line.length) {
-    n++;
-    if (n + 1 == (int)ms.size()) {
-      break;
-    }
-  }
-  return n;
+typedef int (*yf)(int, const std::vector<monkey_map>&);
+
+int prev_y(int y, const std::vector<monkey_map>& ms) {
+  return y == 0 ? ms.size() - 1 : y - 1;
 }
 
-int find_first(int y, const std::vector<monkey_map>& ms) {
-  const monkey_map& r = ms[y];
-  int n = y;
-  while (n > 0 && ms[n].start + ms[n].line.length == r.start + r.line.length) {
-    n--;
-    if (n == 0)
-      break;
-  }
-  return n;
+int next_y(int y, const std::vector<monkey_map>& ms) {
+  return y == (int) ms.size() - 1 ? 0 : y + 1;
 }
 
-int find_next(int y, const std::vector<monkey_map>& ms, facing f) {
-  int first = find_first(y, ms);
-  int last = find_last(y, ms);
-  if (f == down) {
-    return last == y ? first : y + 1;
-  }
-  if (f == up) {
-    return first = y ? last : y - 1;
+int find_next(int x, int y, const std::vector<monkey_map>& ms, yf f) {
+  auto ax = absolute_x(x, ms[y]);
+  while (true) {
+    y = f(y, ms);
+    const monkey_map& r = ms[y];
+    if (ax >= r.start && ax < r.start + (int) r.line.length) {
+      return y;
+    }
   }
-  return y;
 }
 
 void go_up(int s, person* p, const std::vector<monkey_map>& ms) {
   if (s > 0) {
+    int ax = absolute_x(p->x, ms[p->y]);
+    int y = find_next(p->x, p->y, ms, prev_y);
+    const monkey_map& r = ms[y];
+    if (*(r.line.line + ax - r.start) == '.') {
+      p->y = y;
+      p->x = ax - r.start;
+      go_up(s - 1, p, ms);
+    }
   }
 }
 
 void go_down(int s, person* p, const std::vector<monkey_map>& ms) {
   if (s > 0) {
+    int ax = absolute_x(p->x, ms[p->y]);
+    int y = find_next(p->x, p->y, ms, next_y);
+    const monkey_map& r = ms[y];
+    if (*(r.line.line + ax - r.start) == '.') {
+      p->y = y;
+      p->x = ax - r.start;
+      go_down(s - 1, p, ms);
+    }
   }
 }
 
 void go_left(int s, person* p, const std::vector<monkey_map>& ms) {
   if (s > 0) {
     const monkey_map& m = ms[p->y];
-    char c = p->x - 1 >= 0 ? *(m.line.line + p->x - 1) : *(m.line.line + m.line.length - 1);
-    if (c == ' ') {
-      printf("brrrr left %d %d\n", p->x, p->y);
-    }
+    int x = p->x - 1 >= 0 ? p->x - 1 : m.line.length - 1;
+    char c = *(m.line.line + x);
     if (c == '.') {
-      p->x -= 1;
+      p->x = x;
       go_left(s - 1, p, ms);
     }
   }
@@ -86,12 +77,10 @@ void go_left(int s, person* p, const std::vector<monkey_map>& ms) {
 void go_right(int s, person* p, const std::vector<monkey_map>& ms) {
   if (s > 0) {
     const monkey_map& m = ms[p->y];
-    char c = p->x + 1 < (int)m.line.length ? *(m.line.line + p->x + 1) : *(m.line.line);
-    if (c == ' ') {
-      printf("brrrr right %d %d\n", p->x, p->y);
-    }
+    int x = p->x + 1 < (int) m.line.length ? p->x + 1 : 0;
+    char c = *(m.line.line + x);
     if (c == '.') {
-      p->x += 1;
+      p->x = x;
       go_right(s - 1, p, ms);
     }
   }
@@ -118,7 +107,7 @@ void travel(person* p, const std::vector<monkey_map>& ms, const route& r) {
   }
 }
 
-std::pair<int, int> day22(line_view file) {
+std::pair<int64_t, int64_t> day22(line_view file) {
   per_line(file, [](line_view lv) {
     const char* p = lv.line;
     if (*p == ' ' || *p == '.' || *p == '#') {
@@ -146,7 +135,11 @@ std::pair<int, int> day22(line_view file) {
   for (auto& r : routes) {
     travel(&p, maps, r);
   }
+  
+  char fs[] = {'>', 'v', '<', '^'};
+  printf("person is at x[%d] y[%d] facing[%c]\n", p.x, p.y, fs[p.f]);
+  int64_t n1 = (p.y + 1) * 1000 + 4 * (p.x + 1) + (int) p.f;
 
-  return {0, 0};
+  return {n1, 0};
 }
 } // namespace aoc2022