--- a/dynprog.cc	Mon Apr 03 22:31:57 2023 +0200
+++ b/dynprog.cc	Mon Apr 03 22:46:24 2023 +0200
@@ -17,399 +17,410 @@
 using MemoKey = tuple<size_t, size_t, size_t>;
 
 class TupleHash : function<size_t(const MemoKey &)> {
-public:
-  size_t operator()(const MemoKey &k) const {
-    return get<0>(k) ^ get<1>(k) ^ get<2>(k);
-  }
+    public:
+        size_t operator()(const MemoKey &k) const {
+            return get<0>(k) ^ get<1>(k) ^ get<2>(k);
+        }
 };
 
 class PairHash : function<size_t(const MemoKey &)> {
-public:
-  template <typename T, typename U>
-  size_t operator()(const pair<T, U> &p) const {
-    return hash<T>{}(p.first) ^ hash<U>{}(p.second);
-  }
+    public:
+        template <typename T, typename U>
+            size_t operator()(const pair<T, U> &p) const {
+                return hash<T>{}(p.first) ^ hash<U>{}(p.second);
+            }
 };
 
 template <typename T>
 size_t lcss_inner(
-    const vector<T> &a, const vector<T> &b, size_t i, size_t j, size_t length,
-    size_t &longest, vector<T> &longest_seq,
-    unordered_map<tuple<size_t, size_t, size_t>, size_t, TupleHash> &cache) {
-  if (i >= a.size() || j >= b.size()) {
-    return length;
-  }
+        const vector<T> &a, const vector<T> &b, size_t i, size_t j, size_t length,
+        size_t &longest, vector<T> &longest_seq,
+        unordered_map<tuple<size_t, size_t, size_t>, size_t, TupleHash> &cache) {
+    if (i >= a.size() || j >= b.size()) {
+        return length;
+    }
 
-  const auto key = make_tuple(i, j, length);
-  if (cache.contains(key)) {
-    return get<1>(*cache.find(key));
-  }
+    const auto key = make_tuple(i, j, length);
+    if (cache.contains(key)) {
+        return get<1>(*cache.find(key));
+    }
 
-  if (a.at(i) == b.at(j)) {
-    // Current (i, j) is member of a common subsequence.
-    longest = max(longest, length + 1);
-    size_t remaining_longest =
-        lcss_inner(a, b, i + 1, j + 1, length + 1, longest, longest_seq, cache);
-    if (remaining_longest == longest) {
-      // This element is part of the longest common subsequence.
-      longest_seq.at(length) = a.at(i);
+    if (a.at(i) == b.at(j)) {
+        // Current (i, j) is member of a common subsequence.
+        longest = max(longest, length + 1);
+        size_t remaining_longest =
+            lcss_inner(a, b, i + 1, j + 1, length + 1, longest, longest_seq, cache);
+        if (remaining_longest == longest) {
+            // This element is part of the longest common subsequence.
+            longest_seq.at(length) = a.at(i);
+        }
+        cache.insert(make_pair(key, remaining_longest));
+        return remaining_longest;
+    } else {
+        // Skip element from a.
+        size_t remaining_longest_skip_a =
+            lcss_inner(a, b, i + 1, j, length, longest, longest_seq, cache);
+        // Skip element from b.
+        size_t remaining_longest_skip_b =
+            lcss_inner(a, b, i, j + 1, length, longest, longest_seq, cache);
+        size_t result = max(remaining_longest_skip_a, remaining_longest_skip_b);
+        cache.insert(make_pair(key, result));
+        return result;
     }
-    cache.insert(make_pair(key, remaining_longest));
-    return remaining_longest;
-  } else {
-    // Skip element from a.
-    size_t remaining_longest_skip_a =
-        lcss_inner(a, b, i + 1, j, length, longest, longest_seq, cache);
-    // Skip element from b.
-    size_t remaining_longest_skip_b =
-        lcss_inner(a, b, i, j + 1, length, longest, longest_seq, cache);
-    size_t result = max(remaining_longest_skip_a, remaining_longest_skip_b);
-    cache.insert(make_pair(key, result));
-    return result;
-  }
 }
 
 template <typename T> vector<T> lcss(const vector<T> &a, const vector<T> &b) {
-  size_t longest = 0;
-  vector<T> longest_seq(min(a.size(), b.size()));
-  unordered_map<tuple<size_t, size_t, size_t>, size_t, TupleHash> cache(100);
-  size_t longest_r = lcss_inner(a, b, 0, 0, 0, longest, longest_seq, cache);
+    size_t longest = 0;
+    vector<T> longest_seq(min(a.size(), b.size()));
+    unordered_map<tuple<size_t, size_t, size_t>, size_t, TupleHash> cache(100);
+    size_t longest_r = lcss_inner(a, b, 0, 0, 0, longest, longest_seq, cache);
 
-  fmt::print("Length: {} / {}\n", longest, longest_r);
+    fmt::print("Length: {} / {}\n", longest, longest_r);
 
-  return longest_seq;
+    return longest_seq;
 }
 // g++ only
-template <typename T, template <typename> typename C>
+    template <typename T, template <typename> typename C>
 void evaluate_lcss(const C<T> &a, const C<T> &b)
-  requires ranges::range<C<T>>
+    requires ranges::range<C<T>>
 {
-  vector<T> va(a.begin(), a.end());
-  vector<T> vb(b.begin(), b.end());
-  auto result = timeit_f(function([&va, &vb]() { return lcss(va, vb); }));
+    vector<T> va(a.begin(), a.end());
+    vector<T> vb(b.begin(), b.end());
+    auto result = timeit_f(function([&va, &vb]() { return lcss(va, vb); }));
 
-  fmt::print("{}\n", va);
-  fmt::print("{}\n", vb);
-  fmt::print("{}\n", result);
+    fmt::print("{}\n", va);
+    fmt::print("{}\n", vb);
+    fmt::print("{}\n", result);
 }
 
 template <typename T>
 size_t longest_increasing_subsequence(const vector<T> &a, size_t i, size_t prev,
-                                      size_t length, size_t &longest,
-                                      vector<size_t> &seqixs) {
-  longest = max(length, longest);
-  if (i >= a.size())
-    return length;
+        size_t length, size_t &longest,
+        vector<size_t> &seqixs) {
+    longest = max(length, longest);
+    if (i >= a.size())
+        return length;
 
-  size_t length_with_current =
-      a.at(i) < a.at(prev) ? length
-                           : longest_increasing_subsequence(
-                                 a, i + 1, i, length + 1, longest, seqixs);
-  size_t length_without_current =
-      longest_increasing_subsequence(a, i + 1, prev, length, longest, seqixs);
-  size_t result = max(length_with_current, length_without_current);
+    size_t length_with_current =
+        a.at(i) < a.at(prev) ? length
+        : longest_increasing_subsequence(
+                a, i + 1, i, length + 1, longest, seqixs);
+    size_t length_without_current =
+        longest_increasing_subsequence(a, i + 1, prev, length, longest, seqixs);
+    size_t result = max(length_with_current, length_without_current);
 
-  if (result == length_with_current && result == longest) {
-    seqixs.at(length) = i;
-  }
-  return result;
+    if (result == length_with_current && result == longest) {
+        seqixs.at(length) = i;
+    }
+    return result;
 }
 
 // Bug: if first element is 0 or negative, may repeat last index in seqixs
 template <typename T>
 T max_sum_incr_subseq(const vector<T> &a, size_t i, size_t prev, size_t length,
-                      T sum, T &highest_sum, vector<size_t> &seqixs) {
-  highest_sum = max(sum, highest_sum);
-  if (i >= a.size())
-    return sum;
+        T sum, T &highest_sum, vector<size_t> &seqixs) {
+    highest_sum = max(sum, highest_sum);
+    if (i >= a.size())
+        return sum;
 
-  T sum_with_this =
-      a.at(i) < a.at(prev)
-          ? sum
-          : max_sum_incr_subseq(a, i + 1, i, length + 1, sum + a.at(i),
-                                highest_sum, seqixs);
-  T sum_without_this =
-      max_sum_incr_subseq(a, i + 1, prev, length, sum, highest_sum, seqixs);
-  T result = max(sum_with_this, sum_without_this);
+    T sum_with_this =
+        a.at(i) < a.at(prev)
+        ? sum
+        : max_sum_incr_subseq(a, i + 1, i, length + 1, sum + a.at(i),
+                highest_sum, seqixs);
+    T sum_without_this =
+        max_sum_incr_subseq(a, i + 1, prev, length, sum, highest_sum, seqixs);
+    T result = max(sum_with_this, sum_without_this);
 
-  if (result == sum_with_this && sum_with_this > sum_without_this &&
-      sum_with_this == highest_sum) {
-    seqixs.at(length) = i;
-  }
+    if (result == sum_with_this && sum_with_this > sum_without_this &&
+            sum_with_this == highest_sum) {
+        seqixs.at(length) = i;
+    }
 
-  return result;
+    return result;
 }
 
-template <typename T, template <typename> typename C>
+    template <typename T, template <typename> typename C>
 void evaluate_liss(const C<T> &v)
-  requires ranges::range<C<T>>
+    requires ranges::range<C<T>>
 {
-  vector<T> a(v.begin(), v.end());
-  size_t longest = 0;
-  vector<size_t> seqixs(a.size());
-  size_t result = timeit_f(
-      [&a, &longest, &seqixs]() -> size_t {
-        return longest_increasing_subsequence(a, 0, 0, 0, longest, seqixs);
-      },
-      "longest incr. subsequence");
+    vector<T> a(v.begin(), v.end());
+    size_t longest = 0;
+    vector<size_t> seqixs(a.size());
+    size_t result = timeit_f(
+            [&a, &longest, &seqixs]() -> size_t {
+            return longest_increasing_subsequence(a, 0, 0, 0, longest, seqixs);
+            },
+            "longest incr. subsequence");
 
-  fmt::print("Longest incr. subsequence has length {}/{} and has indices: {}\n",
-             longest, result, seqixs);
+    fmt::print("Longest incr. subsequence has length {}/{} and has indices: {}\n",
+            longest, result, seqixs);
 
-  vector<T> seq(longest);
-  for (size_t i = 0; i < seq.size(); i++)
-    seq.at(i) = a.at(seqixs.at(i));
-  fmt::print("Longest incr. subsequence is: {}\n", seq);
+    vector<T> seq(longest);
+    for (size_t i = 0; i < seq.size(); i++)
+        seq.at(i) = a.at(seqixs.at(i));
+    fmt::print("Longest incr. subsequence is: {}\n", seq);
 }
 
-template <typename T, template <typename> typename C>
+    template <typename T, template <typename> typename C>
 void evaluate_msis(const C<T> &v)
-  requires ranges::range<C<T>>
+    requires ranges::range<C<T>>
 {
-  vector<T> a(v.begin(), v.end());
-  T highest = 0;
-  vector<size_t> seqixs(a.size());
-  size_t result = timeit_f(
-      [&a, &highest, &seqixs]() -> size_t {
-        return max_sum_incr_subseq(a, 0, 0, 0, static_cast<T>(0), highest,
-                                   seqixs);
-      },
-      "max sum incr. subsequence");
+    vector<T> a(v.begin(), v.end());
+    T highest = 0;
+    vector<size_t> seqixs(a.size());
+    size_t result = timeit_f(
+            [&a, &highest, &seqixs]() -> size_t {
+            return max_sum_incr_subseq(a, 0, 0, 0, static_cast<T>(0), highest,
+                    seqixs);
+            },
+            "max sum incr. subsequence");
 
-  fmt::print(
-      "Max incr sum subseq subsequence has sum {}/{} and has indices: {}\n",
-      highest, result, seqixs);
+    fmt::print(
+            "Max incr sum subseq subsequence has sum {}/{} and has indices: {}\n",
+            highest, result, seqixs);
 
-  vector<T> seq(seqixs.size());
-  for (size_t i = 0; i < seq.size(); i++) {
-    if (i > 0 && seqixs.at(i) == 0)
-      break;
-    seq.at(i) = a.at(seqixs.at(i));
-  }
-  fmt::print("Max sum incr. subsequence is: {}\n", seq);
+    vector<T> seq(seqixs.size());
+    for (size_t i = 0; i < seq.size(); i++) {
+        if (i > 0 && seqixs.at(i) == 0)
+            break;
+        seq.at(i) = a.at(seqixs.at(i));
+    }
+    fmt::print("Max sum incr. subsequence is: {}\n", seq);
 }
 
 template <typename T> string digits2string(const vector<T> &v) {
-  ostringstream s;
-  for (const T &e : v) {
-    s << e;
-  }
-  return s.str();
+    ostringstream s;
+    for (const T &e : v) {
+        s << e;
+    }
+    return s.str();
 }
 
 void keypad(const unordered_map<int, vector<int>> &adj, vector<int> seq,
-            int n) {
-  if (n <= 0) {
-    cout << digits2string(seq) << " ";
-  } else {
-    if (seq.empty()) {
-      for (int k : views::keys(adj)) {
-        keypad(adj, vector<int>{k}, n - 1);
-      }
+        int n) {
+    if (n <= 0) {
+        cout << digits2string(seq) << " ";
     } else {
-      int last = seq.back();
-      const vector<int> &neighbors = adj.at(last);
-      for (int neigh : neighbors) {
-        seq.push_back(neigh);
-        keypad(adj, seq, n - 1);
-        seq.pop_back();
-      }
+        if (seq.empty()) {
+            for (int k : views::keys(adj)) {
+                keypad(adj, vector<int>{k}, n - 1);
+            }
+        } else {
+            int last = seq.back();
+            const vector<int> &neighbors = adj.at(last);
+            for (int neigh : neighbors) {
+                seq.push_back(neigh);
+                keypad(adj, seq, n - 1);
+                seq.pop_back();
+            }
+        }
     }
-  }
 }
 
 size_t count_keypad(const unordered_map<int, vector<int>> &adj, int last, int n,
-                    unordered_map<pair<int, int>, size_t, PairHash> &memo) {
-  if (n == 0)
-    return 1;
+        unordered_map<pair<int, int>, size_t, PairHash> &memo) {
+    if (n == 0)
+        return 1;
 
-  const auto memopos = memo.find(make_pair(last, n));
-  if (memopos != memo.end())
-    return memopos->second;
+    const auto memopos = memo.find(make_pair(last, n));
+    if (memopos != memo.end())
+        return memopos->second;
 
-  if (last < 0) {
-    const auto ks = views::keys(adj);
-    auto tf = views::transform(ks, [&adj, &memo, n](int key) -> size_t {
-      return count_keypad(adj, key, n - 1, memo);
-    });
-    size_t result = reduce(tf.begin(), tf.end());
-    memo.insert(make_pair(make_pair(last, n), result));
-    return result;
-  } else {
-    const auto &neighbors = adj.at(last);
-    const auto counts =
-        views::transform(neighbors, [&adj, &memo, n](int neigh) -> size_t {
-          return count_keypad(adj, neigh, n - 1, memo);
-        });
-    size_t result = reduce(counts.begin(), counts.end());
-    memo.insert(make_pair(make_pair(last, n), result));
-    return result;
-  }
+    if (last < 0) {
+        const auto ks = views::keys(adj);
+        auto tf = views::transform(ks, [&adj, &memo, n](int key) -> size_t {
+                return count_keypad(adj, key, n - 1, memo);
+                });
+        size_t result = reduce(tf.begin(), tf.end());
+        memo.insert(make_pair(make_pair(last, n), result));
+        return result;
+    } else {
+        const auto &neighbors = adj.at(last);
+        const auto counts =
+            views::transform(neighbors, [&adj, &memo, n](int neigh) -> size_t {
+                    return count_keypad(adj, neigh, n - 1, memo);
+                    });
+        size_t result = reduce(counts.begin(), counts.end());
+        memo.insert(make_pair(make_pair(last, n), result));
+        return result;
+    }
 }
 
 // https://www.techiedelight.com/count-total-possible-combinations-n-digit-numbers-mobile-keypad/
 void evaluate_keypad(size_t n = 2) {
-  unordered_map<int, vector<int>> adjacency{
-      {1, {1, 2, 4}},    {2, {1, 2, 3, 5}},    {3, {2, 3, 6}},
-      {4, {1, 4, 5, 7}}, {5, {2, 5, 6, 8, 4}}, {6, {3, 6, 5, 9}},
-      {7, {4, 7, 8}},    {8, {7, 5, 8, 9, 0}}, {9, {6, 8, 9}},
-      {0, {0, 8}},
-  };
-  unordered_map<pair<int, int>, size_t, PairHash> memo;
+    unordered_map<int, vector<int>> adjacency{
+        {1, {1, 2, 4}},    {2, {1, 2, 3, 5}},    {3, {2, 3, 6}},
+            {4, {1, 4, 5, 7}}, {5, {2, 5, 6, 8, 4}}, {6, {3, 6, 5, 9}},
+            {7, {4, 7, 8}},    {8, {7, 5, 8, 9, 0}}, {9, {6, 8, 9}},
+            {0, {0, 8}},
+    };
+    unordered_map<pair<int, int>, size_t, PairHash> memo;
 
-  // keypad(adjacency, vector<int>{}, n);
-  cout << endl;
+    // keypad(adjacency, vector<int>{}, n);
+    cout << endl;
 
-  size_t ck = timeit_f(([&adjacency, &memo, n]() {
-                         return count_keypad(adjacency, -1, n, memo);
-                       }),
-                       "count_keypad");
-  fmt::print("count = {}\n", ck);
+    size_t ck = timeit_f(([&adjacency, &memo, n]() {
+                return count_keypad(adjacency, -1, n, memo);
+                }),
+            "count_keypad");
+    fmt::print("count = {}\n", ck);
 
-  fmt::print("memoize count = {}\n", memo.size());
+    fmt::print("memoize count = {}\n", memo.size());
 }
 
 bool wildcard_matches(string::const_iterator pbegin,
-                      string::const_iterator pend,
-                      string::const_iterator sbegin,
-                      string::const_iterator send) {
-  // Pattern finished but string not finished.
-  if (pbegin == pend && sbegin < send) {
+        string::const_iterator pend,
+        string::const_iterator sbegin,
+        string::const_iterator send) {
+    // Pattern finished but string not finished.
+    if (pbegin == pend && sbegin < send) {
+        return false;
+    }
+    // String ended and pattern not definitely ended.
+    if (sbegin == send) {
+        return pbegin == pend;
+    }
+    if (*pbegin == *sbegin || *pbegin == '?') {
+        return wildcard_matches(pbegin + 1, pend, sbegin + 1, send);
+    }
+    if (*pbegin == '*') {
+        // Keep or consume wildcard.
+        return wildcard_matches(pbegin, pend, sbegin + 1, send) ||
+            wildcard_matches(pbegin + 1, pend, sbegin + 1, send);
+    }
     return false;
-  }
-  // String ended and pattern not definitely ended.
-  if (sbegin == send) {
-    return pbegin == pend;
-  }
-  if (*pbegin == *sbegin || *pbegin == '?') {
-    return wildcard_matches(pbegin + 1, pend, sbegin + 1, send);
-  }
-  if (*pbegin == '*') {
-    // Keep or consume wildcard.
-    return wildcard_matches(pbegin, pend, sbegin + 1, send) ||
-           wildcard_matches(pbegin + 1, pend, sbegin + 1, send);
-  }
-  return false;
 }
 
 bool wildcard_matches(const string &pattern, const string &str) {
-  return wildcard_matches(pattern.begin(), pattern.end(), str.begin(),
-                          str.end());
+    return wildcard_matches(pattern.begin(), pattern.end(), str.begin(),
+            str.end());
 }
 
 void evaluate_wildcard_matches() {
-  vector<pair<string, string>> tests{
-      {"xyxzzxy", "x***y"},
-      {"xyxzzxy", "x***x"},
-      {"xyxzzxy", "x***x?"},
-      {"xyxzzxy", "*"},
-  };
+    vector<pair<string, string>> tests{
+        {"xyxzzxy", "x***y"},
+            {"xyxzzxy", "x***x"},
+            {"xyxzzxy", "x***x?"},
+            {"xyxzzxy", "*"},
+    };
 
-  for (const auto &p : tests) {
-    benchmarkit_f([&]() { wildcard_matches(p.second, p.first); },
-                  "wildcard_matches");
-    fmt::print("{} matches {} ? => {}\n", p.first, p.second,
-               wildcard_matches(p.second, p.first));
-  }
+    for (const auto &p : tests) {
+        benchmarkit_f([&]() { wildcard_matches(p.second, p.first); },
+                "wildcard_matches");
+        fmt::print("{} matches {} ? => {}\n", p.first, p.second,
+                wildcard_matches(p.second, p.first));
+    }
 }
 
 // TODO: store cutting way
 int rodcutting_prod_max(int length) {
-  if (length <= 1)
-    return 1;
-  int max_len = 0;
-  for (int this_part = length; this_part > 0; this_part--) {
-    max_len = max(max_len, this_part * rodcutting_prod_max(length - this_part));
-  }
-  return max_len;
+    if (length <= 1)
+        return 1;
+    int max_len = 0;
+    for (int this_part = length; this_part > 0; this_part--) {
+        max_len = max(max_len, this_part * rodcutting_prod_max(length - this_part));
+    }
+    return max_len;
 }
 
 // https://www.techiedelight.com/coin-change-problem-find-total-number-ways-get-denomination-coins/
 int coin_change_problem(const vector<int> &coins, int amount_left,
-                        vector<int> &current,
-                        vector<vector<int>> &possibilities) {
-  if (amount_left == 0 && !current.empty()) {
-    possibilities.push_back(current);
-    return 1;
-  } else if (amount_left > 0) {
-    int possible_count = 0;
-    for (int coin : coins) {
-      if (coin > amount_left)
-        continue;
-      if (!current.empty() && coin < *(current.end() - 1))
-        continue;
-      current.push_back(coin);
-      possible_count += coin_change_problem(coins, amount_left - coin, current,
-                                            possibilities);
-      current.pop_back();
+        vector<int> &current,
+        vector<vector<int>> &possibilities) {
+    if (amount_left == 0 && !current.empty()) {
+        possibilities.push_back(current);
+        return 1;
+    } else if (amount_left > 0) {
+        int possible_count = 0;
+        for (int coin : coins) {
+            if (coin > amount_left)
+                continue;
+            if (!current.empty() && coin < *(current.end() - 1))
+                continue;
+            current.push_back(coin);
+            possible_count += coin_change_problem(coins, amount_left - coin, current,
+                    possibilities);
+            current.pop_back();
+        }
+        return possible_count;
     }
-    return possible_count;
-  }
-  return 0;
+    return 0;
 }
 
 void evaluate_coin_change() {
-  vector<int> coins{1, 3, 5, 7};
-  int amount = 8;
-  vector<int> current{};
-  vector<vector<int>> possibilities{};
+    vector<int> coins{1, 3, 5, 7};
+    int amount = 8;
+    vector<int> current{};
+    vector<vector<int>> possibilities{};
 
-  int N = timeit_f([&]() -> int {
-    return coin_change_problem(coins, amount, current, possibilities);
-  });
+    int N = timeit_f([&]() -> int {
+            return coin_change_problem(coins, amount, current, possibilities);
+            });
 
-  fmt::print("{}: {}\n", N, possibilities);
+    fmt::print("{}: {}\n", N, possibilities);
 }
 
 template <typename R, typename RT>
-  requires range<R> && is_same_v<range_value_t<R>, RT> bool
-three_partition_inner(const R &r, size_t ix, RT a, RT b, RT c) {
-  if (r.begin() + ix == r.end()) {
-    return (a == b) && (b == c);
-  }
-  using It = decltype(std::ranges::begin(r));
+requires range<R> && is_same_v<range_value_t<R>, RT> bool
+three_partition_inner(const R &r, size_t ix, RT a, RT b, RT c, unordered_map<tuple<int,int,int>, bool, TupleHash>& memo) {
+    if (r.begin() + ix == r.end()) {
+        return (a == b) && (b == c);
+    }
+
+    //auto key = make_tuple(a, b, c);
+    //auto entry = memo.find(key);
+    //if (entry != memo.end()) {
+    //    return entry->second;
+    //}
 
-  It beg = r.begin() + ix;
-  RT val = *beg;
+    using It = decltype(std::ranges::begin(r));
+
+    //fmt::print("{} : {} {} {}\n", ix, a, b, c);
+    It beg = r.begin() + ix;
+    RT val = *beg;
 
-  // Check three cases.
-  return three_partition_inner(r, ix + 1, a + val, b, c) ||
-         three_partition_inner(r, ix + 1, a, b + val, c) ||
-         three_partition_inner(r, ix + 1, a, b, c + val);
+    // Check three cases.
+    bool result = three_partition_inner(r, ix + 1, a + val, b, c, memo) ||
+        three_partition_inner(r, ix + 1, a, b + val, c, memo) ||
+        three_partition_inner(r, ix + 1, a, b, c + val, memo);
+    //memo.insert({key, result});
+    return result;
 }
 
 template <typename R>
-  requires range<R> bool
+requires range<R> bool
 three_partition(const R &r) {
-  using T = range_value_t<R>;
-  return three_partition_inner<R, T>(r, 0, T(0), T(0), T(0));
+    using T = range_value_t<R>;
+    unordered_map<tuple<int,int,int>, bool, TupleHash> memo;
+    return three_partition_inner<R, T>(r, 0, T(0), T(0), T(0), memo);
 }
 
 int three_partition_main(void) {
-  vector<int> a{50, 49, 1, 98, 1, 1, 90, 3, 3, 4};
-  fmt::print("{}: {}\n", a, timeit_f([&a]() { return three_partition(a); }));
-  return 0;
+    vector<int> a{50, 49, 1, 98, 1, 1, 90, 3, 3, 4};
+    fmt::print("{}: {}\n", a, timeit_f([&a]() { return three_partition(a); }));
+    return 0;
 }
 
 int lcss_main(void) {
 
-  vector<int> a{1, 6, 2, -1, 3, 55, 2, 4, 23, 5, 6, 7, 8, 9, 10};
-  vector<int> b{-3, 1, 5, 7, 2, 4, -1, 3, 6, 7, 9, 11, 10};
+    vector<int> a{1, 6, 2, -1, 3, 55, 2, 4, 23, 5, 6, 7, 8, 9, 10};
+    vector<int> b{-3, 1, 5, 7, 2, 4, -1, 3, 6, 7, 9, 11, 10};
 
-  evaluate_lcss(a, b);
-  evaluate_lcss(views::single(11), views::single(11));
-  return 0;
+    evaluate_lcss(a, b);
+    evaluate_lcss(views::single(11), views::single(11));
+    return 0;
 }
 
 int liss_main(void) {
-  vector<int> a{0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11};
-  // Expect: 0,2,6,9,13 or ,11
-  // or 0,4,6,9,13
-  evaluate_liss(a);
-  return 0;
+    vector<int> a{0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11};
+    // Expect: 0,2,6,9,13 or ,11
+    // or 0,4,6,9,13
+    evaluate_liss(a);
+    return 0;
 }
 
 int main(void) {
-  three_partition_main();
-  return 0;
+    three_partition_main();
+    return 0;
 }