From 32598f64a9ba863b90234a15147ac7d40e5a2fc9 Mon Sep 17 00:00:00 2001
From: Matthew Gretton-Dann <matt@gretton-dann.org.uk>
Date: Mon, 13 Dec 2021 17:25:46 +0000
Subject: [PATCH] Add 2017 day 6 puzzles

---
 2017/puzzle-06-01.cc | 58 +++++++++++++++++++++++++++++++++++
 2017/puzzle-06-02.cc | 72 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 130 insertions(+)
 create mode 100644 2017/puzzle-06-01.cc
 create mode 100644 2017/puzzle-06-02.cc

diff --git a/2017/puzzle-06-01.cc b/2017/puzzle-06-01.cc
new file mode 100644
index 0000000..b7254a3
--- /dev/null
+++ b/2017/puzzle-06-01.cc
@@ -0,0 +1,58 @@
+#include <iostream>
+#include <string>
+#include <vector>
+
+using UInt = unsigned long;
+using LoadingVector = std::vector<UInt>;
+
+auto split(std::string const& line, char c) -> LoadingVector
+{
+  LoadingVector result;
+  std::size_t idx{0};
+  while (idx != std::string::npos) {
+    auto next{line.find(c, idx)};
+    if (next == std::string::npos) {
+      result.push_back(std::stoul(line.substr(idx)));
+      idx = next;
+    }
+    else {
+      result.push_back(std::stoul(line.substr(idx, next - idx)));
+      idx = next + 1;
+    }
+  }
+  return result;
+}
+
+auto main() -> int
+{
+  std::string line;
+  if (!std::getline(std::cin, line)) {
+    std::cerr << "Unable ot read line\n";
+    return 1;
+  }
+
+  LoadingVector load{split(line, '\t')};
+
+  std::vector<LoadingVector> states;
+
+  do {
+    states.push_back(load);
+    auto it{std::max_element(load.begin(), load.end())};
+    auto amt{*it};
+    *it = 0;
+    for (auto& it2 : load) {
+      it2 += amt / load.size();
+    }
+    amt %= load.size();
+    while (amt != 0) {
+      ++it;
+      if (it == load.end()) {
+        it = load.begin();
+      }
+      ++*it;
+      --amt;
+    }
+  } while (std::find(states.begin(), states.end(), load) == states.end());
+  std::cout << "Count: " << states.size() << '\n';
+  return 0;
+}
diff --git a/2017/puzzle-06-02.cc b/2017/puzzle-06-02.cc
new file mode 100644
index 0000000..d229f92
--- /dev/null
+++ b/2017/puzzle-06-02.cc
@@ -0,0 +1,72 @@
+#include <iostream>
+#include <string>
+#include <vector>
+
+using UInt = unsigned long;
+using LoadingVector = std::vector<UInt>;
+
+auto split(std::string const& line, char c) -> LoadingVector
+{
+  LoadingVector result;
+  std::size_t idx{0};
+  while (idx != std::string::npos) {
+    auto next{line.find(c, idx)};
+    if (next == std::string::npos) {
+      result.push_back(std::stoul(line.substr(idx)));
+      idx = next;
+    }
+    else {
+      result.push_back(std::stoul(line.substr(idx, next - idx)));
+      idx = next + 1;
+    }
+  }
+  return result;
+}
+
+void redistribute(LoadingVector& load)
+{
+  auto it{std::max_element(load.begin(), load.end())};
+  auto amt{*it};
+  *it = 0;
+  for (auto& it2 : load) {
+    it2 += amt / load.size();
+  }
+  amt %= load.size();
+  while (amt != 0) {
+    ++it;
+    if (it == load.end()) {
+      it = load.begin();
+    }
+    ++*it;
+    --amt;
+  }
+}
+
+auto main() -> int
+{
+  std::string line;
+  if (!std::getline(std::cin, line)) {
+    std::cerr << "Unable ot read line\n";
+    return 1;
+  }
+
+  LoadingVector load{split(line, '\t')};
+
+  std::vector<LoadingVector> states;
+
+  do {
+    states.push_back(load);
+    redistribute(load);
+  } while (std::find(states.begin(), states.end(), load) == states.end());
+  std::cout << "Count: " << states.size() << '\n';
+
+  auto count{0};
+  auto load2{load};
+  do {
+    redistribute(load2);
+    ++count;
+  } while (load != load2);
+
+  std::cout << "Loop size: " << count << '\n';
+  return 0;
+}