aoc24: day02b not working

aoc.cpp

@@ -12,7 +12,8 @@ using levels_t  = std::vector<std::int32_t>;
 using reports_t = std::vector<levels_t>;
 
 auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
-    constexpr auto filename = "./dat/24/ex/02.txt";
+    // constexpr auto filename = "./dat/24/ex/02.txt";
+    constexpr auto filename = "./tmp.txt";
     std::ifstream strm{filename, std::ios::in | std::ios::binary};
     if (!strm.is_open()) {
         fmt::print("Error opening file: {}\n", filename);
@@ -41,12 +42,6 @@ auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
         strm.get();
     }
 
-    // auto diff = reports | std::views::transform([](auto const& levels) {
-    //     return levels | std::views::slide(2) | std::views::transform([](auto pair) {
-    //         return pair[1] - pair[0];
-    //     });
-    // });
-
     auto diff = reports | std::views::transform([](auto const& levels) {
         return levels | std::views::adjacent_transform<2>([](auto const& a, auto const& b) {
             return b - a;
@@ -71,21 +66,77 @@ auto main([[maybe_unused]]int argc, [[maybe_unused]]char const* argv[]) -> int {
 
     fmt::print("Part A: {}\n", safe_reports);
 
-    for (auto levels : reports) {
+    auto lefts = std::views::zip(diff, reports) | std::views::filter([](auto const& pair) {
-        for (auto level : levels) {
+        auto const& [d, l] = pair;
-            fmt::print("{} ", level);
+        auto const n = std::ranges::all_of(d, [](auto v) { return v < 0; });
-        }
+        auto const p = std::ranges::all_of(d, [](auto v) { return v > 0; });
-        fmt::print("\n");
+        return !(n || p);
-    }
+    }) | std::views::transform([](auto const& pair) {
+        auto const& [d, l] = pair;
+        return l;
+     });
 
-    fmt::print("--------------------------------------------------------------------------------\n");
+    auto masks = diff | std::views::filter([](auto const& vec) {
+        auto const n = std::ranges::all_of(vec, [](auto v) { return v < 0; });
+        auto const p = std::ranges::all_of(vec, [](auto v) { return v > 0; });
+        return !(n || p);
+    }) | std::views::transform([](auto const& vec) {
+        auto const p = std::count_if(std::begin(vec), std::end(vec), [](auto const& v) { return v >= 0; });
+        auto const n = std::count_if(std::begin(vec), std::end(vec), [](auto const& v) { return v < 0; });
+        auto mask = vec | std::views::transform([&](auto const& v) {
+                if (p > n) return v >= 0 ? 1 : 0;
+                else return v < 0 ? 1 : 0;
+            }) | std::ranges::to<std::vector>();
+        mask.push_back(1);
+        return mask;
+    });
 
-    for (auto levels : diff) {
+    auto const remain_reports = std::views::zip(masks, lefts)
-        for (auto level : levels) {
+            | std::views::filter([](auto const& pair) {
-            fmt::print("{} ", level);
+                auto const& [mask, level] = pair;
-        }
+                auto const n = std::count_if(std::begin(mask), std::end(mask), [](auto const& v) { return v == 0; });
-        fmt::print("\n");
+                return n == 1;
-    }
+            })
+            | std::views::transform([](auto const& pair){
+               auto const& [mask, level] = pair;
+
+               return std::views::zip(mask, level) | std::views::filter([](auto const& pair) {
+                    auto const& [m, v] = pair;
+                    return m == 1;
+               }) | std::views::transform([](auto const& pair) {
+                    auto const& [m, v] = pair;
+                    return v;
+               }) | std::ranges::to<std::vector>();
+            })
+            | std::ranges::to<std::vector>();
+
+    auto rem_diff = remain_reports | std::views::transform([](auto const& vec) {
+        return vec | std::views::adjacent_transform<2>([](auto const& a, auto const& b) { return b - a; });
+    });
+
+    auto safe_rems_vec = rem_diff | std::views::transform([](auto const& vec) {
+        return vec | std::views::filter([](auto const& a) {
+            return std::abs(a) <= 3;
+        }) | std::ranges::to<std::vector>();
+    }) | std::ranges::to<std::vector>();
+
+    auto safe_rems = safe_rems_vec | std::views::filter([](auto const& vec) {
+        return vec.size() > 0;
+    }) | std::views::filter([](auto const& vec) {
+        auto const n = std::ranges::all_of(vec, [](auto v) { return v < 0; });
+        auto const p = std::ranges::all_of(vec, [](auto v) { return v > 0; });
+        return n || p;
+    });
+
+    auto const safe_reports_rem = std::ranges::distance(safe_rems);
+
+    // for (auto rep : safe_rems) {
+    //     for (auto v : rep) {
+    //         fmt::print("{} ", v);
+    //     }
+    //     fmt::print("\n");
+    // }
+    fmt::print("Part B: {}\n", safe_reports + safe_reports_rem);
 
     return 0;
 }