advent2024

commit 328ed172dcc9451f8ab3bb440f2374666af52432
parent 4343c0b16e751b1ec4e02f3e2c45ccf6dafe4d77
Author: bsandro <email@bsandro.tech>
Date:   Thu, 26 Dec 2024 09:13:17 +0200

Day 12 p2

Diffstat:
M
day12/main.cpp
 | 
60
+++++++++---------------------------------------------------

1 file changed, 9 insertions(+), 51 deletions(-)
diff --git a/day12/main.cpp b/day12/main.cpp
@@ -49,10 +49,8 @@ public:
                 Vec2 pd(p.first+dir.first, p.second+dir.second);
                 if (this->has(pd)) {
                     cnt--;
-                    //std::printf("[%d,%d] has neighbor [%d,%d]\n", p.first, p.second, pd.first, pd.second);
                 }
             }
-            //std::printf("(%ld)\n", cnt);
             per+=cnt;
         }
         return per;
@@ -60,52 +58,16 @@ public:
 
     int64_t sides() const {
         int64_t cnt = 0;
-        std::vector<Vec2> n,e,s,w;
         for (const auto &p : *this) {
-            if (!this->has(Vec2(p.first+1, p.second))) e.push_back(p);
-            if (!this->has(Vec2(p.first-1, p.second))) w.push_back(p);
-            if (!this->has(Vec2(p.first, p.second+1))) s.push_back(p);
-            if (!this->has(Vec2(p.first, p.second-1))) n.push_back(p);
-        }
-        std::sort(n.begin(), n.end(), [](auto &p1, auto &p2){ return p1.second<p2.second; });
-        std::sort(s.begin(), s.end(), [](auto &p1, auto &p2){ return p1.second<p2.second; });
-        std::sort(e.begin(), e.end(), [](auto &p1, auto &p2){ return p1.first<p2.first; });
-        std::sort(w.begin(), w.end(), [](auto &p1, auto &p2){ return p1.first<p2.first; });
-
-        /*std::printf("east:");
-        for (auto &p:e) {
-            std::printf("[%d,%d]", p.first, p.second);
-        }
-        std::printf("\n");*/
+            if (!this->has(Vec2(p.first+1, p.second))&&!this->has(Vec2(p.first, p.second-1))) cnt++;
+            if (!this->has(Vec2(p.first+1, p.second))&&!this->has(Vec2(p.first, p.second+1))) cnt++;
+            if (!this->has(Vec2(p.first-1, p.second))&&!this->has(Vec2(p.first, p.second+1))) cnt++;
+            if (!this->has(Vec2(p.first-1, p.second))&&!this->has(Vec2(p.first, p.second-1))) cnt++;
 
-        int v=-1;
-        int prev=-1;
-        for (auto &p : n) {
-            if (p.second!=v || std::abs(prev-p.first)>1) { cnt++; }
-            v=p.second;
-            prev=p.first;
-        }
-        v=-1;
-        prev=-1;
-        for (auto &p : s) {
-            if (p.second!=v || std::abs(prev-p.first)>1) cnt++;
-            v=p.second;
-            prev=p.first;
-        }
-        v=-1;
-        prev=-1;
-        for (auto &p : e) {
-            if (p.first!=v || std::abs(prev-p.second)>1) cnt++;
-            v=p.first;
-            prev=p.second;
-        }
-        //std::printf("north+south+east count:%ld\n", cnt);
-        v=-1;
-        prev=-1;
-        for (auto &p : w) {
-            if (p.first!=v || std::abs(prev-p.second)>1) cnt++;
-            v=p.first;
-            prev=p.second;
+            if (!this->has(Vec2(p.first+1, p.second-1))&&this->has(Vec2(p.first+1, p.second))&&this->has(Vec2(p.first, p.second-1))) cnt++;
+            if (!this->has(Vec2(p.first+1, p.second+1))&&this->has(Vec2(p.first+1, p.second))&&this->has(Vec2(p.first, p.second+1))) cnt++;
+            if (!this->has(Vec2(p.first-1, p.second+1))&&this->has(Vec2(p.first-1, p.second))&&this->has(Vec2(p.first, p.second+1))) cnt++;
+            if (!this->has(Vec2(p.first-1, p.second-1))&&this->has(Vec2(p.first-1, p.second))&&this->has(Vec2(p.first, p.second-1))) cnt++;
         }
         return cnt;
     }
@@ -116,8 +78,7 @@ public:
         }
     }
 };
-// 1046941 too high
-// 918855 too high
+
 template<typename T>
 T read_file(const std::string &path) {
     std::ifstream ifs(path, std::ios::binary);
@@ -152,9 +113,6 @@ std::pair<int64_t, int64_t> solve(Data &input [[ maybe_unused ]]) {
             if (!processed.has(Vec2(x, y))) {
                 Plot p = findPlot(input, Vec2(x,y));
                 processed.insert(p.begin(), p.end());
-                std::printf("-------------\nfound plot (%c):\n", input[y][x]);
-                p.print();
-                std::printf("\nsides: %ld, area: %ld\n", p.sides(), p.area());
                 p1sum += p.area() * p.perimeter();
                 p2sum += p.area() * p.sides();
             }