Revert "fix vector memory leak"

This reverts commit 0787e2c1

cosets/src/tc.cpp

@@ -52,35 +52,34 @@ struct Table {
    }
 
    std::vector<std::vector<int>> words() {
-      std::vector<std::vector<int>> vecs(size());
-      std::vector<bool> done_vecs(size());
-      done_vecs[0] = true;
-
-      bool done = false;
-      while (!done) {
-         done = true;
+      std::vector<std::vector<int> *> vecs(size());
+      vecs[0] = new std::vector<int>();
 
+      while (std::find(vecs.begin(), vecs.end(), nullptr) != vecs.end()) {
          for (int from = 0; from < (int) vecs.size(); ++from) {
-            if (done_vecs[from]) {
-               done = false;
+            std::vector<int> *word = vecs[from];
+            if (word == nullptr) {
                continue;
             }
-            std::vector<int> word = vecs[from];
 
             for (int gen = 0; gen < (int) N; ++gen) {
                int to = get(from, gen);
-               if (done_vecs[to]) {
+               if (vecs[to] != nullptr) {
                   continue;
                }
 
-               done_vecs[to] = true;
-               vecs[to].assign(word.size() + 1, gen);
-               std::copy(word.begin(), word.end(), vecs[to].begin());
+               vecs[to] = new std::vector<int>(*word);
+               vecs[to]->push_back(gen);
             }
          }
       }
 
-      return vecs;
+      std::vector<std::vector<int>> res(size());
+      for (int i = 0; i < (int) size(); ++i) {
+         res[i] = *vecs[i];
+      }
+
+      return res;
    }
 };