Implement longest run

Author: slava-sh

A.cpp

@@ -19,6 +19,7 @@ const double NORMAL_PEAK          = 580;
 const double NORMAL_BOOST         = 0.03;
 const double SMALL_THRESHOLD      = 350;
 const double SMALL_BOOST          = 0.0228;
+const int    MIN_LONGEST_RUN      = 200;
 
 struct SigmoidClassifier {
     const double lo;
@@ -650,6 +651,20 @@ struct DSU {
     }
 };
 
+int longest_run(const vector< int >& a, const vector< int >& b) {
+    int result = 0;
+    for (int i = 0, na = a.size(); i < na; ++i) {
+        for (int j = 0, nb = b.size(); j < nb; ++j) {
+            int run = 0;
+            while (i + run < na && j + run < nb && a[i + run] == b[j + run]) {
+                ++run;
+            }
+            result = max(result, run);
+        }
+    }
+    return result;
+}
+
 int main() {
     Tokens special_tokens = {
         VALUE_TOKEN,
@@ -717,7 +732,8 @@ int main() {
             auto dist = levenshtein_distance(i->fingerprint, j->fingerprint);
             auto size = (double) (i->fingerprint.size() + j->fingerprint.size()) / 2;
             auto ratio = dist / size;
-            bool similar = classify(size, ratio);
+            bool similar = classify(size, ratio) ||
+                longest_run(i->fingerprint, j->fingerprint) >= MIN_LONGEST_RUN;
             if (similar) {
                 ans.unite(i->id, j->id);
             }