seems to be working

cosets/src/tc.cpp

@@ -1,67 +1,22 @@
 #include <iostream>
 #include <vector>
+#include <iomanip>
+#include <cmath>
 
-template<int N>
-struct Row;
 
-template<int N>
-struct Table;
-
-template<int N>
-struct Row {
-   std::vector<int>::const_iterator l;
-   std::vector<int>::const_iterator r;
-
-   int from;
-   int to;
-
-   Row(const std::vector<int> &vec, int from, int to) {
-      this->l = vec.begin();
-      this->r = vec.end() - 1;
-      this->from = from;
-      this->to = to;
-   }
-
-   bool learn(Table<N> &table) {
-      if (r - l == 0) {
-         return false;
-      }
-
-      while (r - l > 0) {
-         int next = table.get(from, *l);
-         if (next < 0) break;
-         l++;
-         from = next;
-      }
-
-      while (r - l > 0) {
-         int next = table.rget(*r, to);
-         if (next < 0) break;
-         r--;
-         to = next;
-      }
-
-      if (r - l == 0) {
-         table.set(from, *l, to);
-         return true;
-      }
-
-      return false;
-   }
-};
-
-template<int N>
 struct Table {
+   int N;
    std::vector<std::vector<int>> fwd;
    std::vector<std::vector<int>> rev;
 
-   Table() {
+   explicit Table(int N) {
       add_row();
+      this->N = N;
    }
 
    void add_row() {
-      fwd.push_back(std::vector<int>(N, -1));
-      rev.push_back(std::vector<int>(N, -1));
+      fwd.emplace_back(N, -1);
+      rev.emplace_back(N, -1);
    }
 
    int add_coset() {
@@ -96,8 +51,49 @@ struct Table {
    }
 };
 
-template<int N>
-std::ostream &operator<<(std::ostream &out, const Row<N> &row) {
+struct Row {
+   std::vector<int>::const_iterator l;
+   std::vector<int>::const_iterator r;
+
+   int from;
+   int to;
+
+   Row(const std::vector<int> &vec, int cos) {
+      this->l = vec.begin();
+      this->r = vec.end() - 1;
+      this->from = cos;
+      this->to = cos;
+   }
+
+   bool learn(Table *table) {
+      if (r - l == 0) {
+         return false;
+      }
+
+      while (r - l > 0) {
+         int next = table->get(from, *l);
+         if (next < 0) break;
+         l++;
+         from = next;
+      }
+
+      while (r - l > 0) {
+         int next = table->rget(*r, to);
+         if (next < 0) break;
+         r--;
+         to = next;
+      }
+
+      if (r - l == 0) {
+         table->set(from, *l, to);
+         return true;
+      }
+
+      return false;
+   }
+};
+
+std::ostream &operator<<(std::ostream &out, const Row &row) {
    out << "[ " << row.from << " | ";
    auto it = row.l;
    while (row.r - it > 0) {
@@ -108,16 +104,17 @@ std::ostream &operator<<(std::ostream &out, const Row<N> &row) {
    return out;
 }
 
-template<int N>
-std::ostream &operator<<(std::ostream &out, const Table<N> &table) {
+std::ostream &operator<<(std::ostream &out, const Table &table) {
+   int k = ceil(log10(table.size()));
+
    out << "[";
    for (unsigned j = 0; j < table.size(); ++j) {
       auto arr = table.fwd[j];
-      out << "[";
-      for (int i = 0; i < N; ++i) {
+      out << " " << std::setw(k) << j << " [";
+      for (int i = 0; i < table.N; ++i) {
          out << arr[i];
 
-         if (i < N - 1)
+         if (i < table.N - 1)
             out << " ";
       }
 
@@ -130,34 +127,56 @@ std::ostream &operator<<(std::ostream &out, const Table<N> &table) {
    return out;
 }
 
+Table *solve(int gens, const std::vector<int> &subgens, const std::vector<std::vector<int>> &rels) {
+   auto *table = new Table(gens);
+
+   for (int gen : subgens)
+      table->set(0, gen, 0);
+
+   std::vector<Row> rows;
+   rows.reserve(rels.size());
+   for (const auto &rel : rels)
+      rows.emplace_back(rel, 0);
+
+   while (!rows.empty()) {
+      while (true) {
+         bool learned = false;
+         for (int i = (int) rows.size() - 1; i >= 0; i--) {
+            if (rows[i].learn(table)) {
+               learned = true;
+               rows.erase(rows.begin() + i);
+            }
+         }
+         if (!learned)
+            break;
+      }
+
+      int i = (int) table->size();
+      if (table->add_coset() > 0) {
+         for (const auto &rel : rels)
+            rows.emplace_back(rel, i);
+      } else {
+         break;
+      }
+   }
+
+   return table;
+}
+
 int main(int argc, char *argv[]) {
    std::vector<std::vector<int>> ids{
       {0, 0},
       {1, 1},
-      {0, 1, 0, 1, 0, 1}
+      {2, 2},
+      {0, 1, 0, 1, 0, 1, 0, 1},
+      {1, 2, 1, 2, 1, 2},
+      {0, 2, 0, 2}
    };
 
-   Row<3> row(ids[2], 0, 0);
-   Table<3> table;
+   Table *table = solve(3, {}, ids);
 
-   table.add_row();
-   table.add_row();
-   table.add_row();
-
-   table.set(0, 0, 1);
-   table.set(1, 1, 2);
-
-   std::cout << table << std::endl;
-   std::cout << row << std::endl;
-
-   row.learn(table);
-   std::cout << row << std::endl;
-
-//   std::cout << table << std::endl;
-//   table.add_coset();
-//   std::cout << table << std::endl;
-//
-//   row.learn(table);
+   std::cout << table->size() << std::endl;
+   std::cout << *table << std::endl;
 
    return 0;
 }