1 files changed, 53 insertions, 0 deletions
diff --git a/src/2017/day7/aoc.cpp b/src/2017/day7/aoc.cpp
index fe3ee2f..86e2e45 100644
--- a/src/2017/day7/aoc.cpp
+++ b/src/2017/day7/aoc.cpp
@@ -1,4 +1,57 @@
 #include "aoc.h"
+#include <unordered_map>
 
 namespace aoc2017 {
+
+void fix_subs(std::unordered_map<line_view, disc*>& ds) {
+  for (auto& kv : ds) {
+    if (kv.second->xp != nullptr) {
+      const char* p1 = kv.second->xp;
+      const char* p = p1;
+      while (*p != '\n') {
+        if (*p == ',') {
+          kv.second->subs.push_back(ds[{p1, p}]);
+          p1 = p + 2;
+        }
+        p++;
+      }
+      kv.second->subs.push_back(ds[{p1, p}]);
+    }
+  }
+}
+
+void depth(disc* d, int* dh) {
+  if (d->subs.size() > 0) {
+    *dh += 1;
+    depth(d->subs[0], dh);
+  }
 }
+
+void day7(line_view file, char name[]) {
+  std::unordered_map<line_view, disc*> ds;
+  per_line(file, [&ds](line_view lv) {
+    const char* p = lv.contains("(");
+    line_view name{lv.line, p - 1};
+    ds.insert({name, new disc{lv, p}});
+    return true;
+  });
+  fix_subs(ds);
+
+  line_view x;
+  int max{INT32_MIN};
+  for (auto& kv : ds) {
+    int d{1};
+    depth(kv.second, &d);
+    if (d > max) {
+      max = d;
+      x = kv.first;
+    }
+  }
+  int i{0};
+  per_char(x, [&name, &i](char c) {
+    name[i++] = c;
+    return true;
+  });
+}
+
+} // namespace aoc2017