git reimport

archive/2016.08/2016.08.04 - unsorted/GroupedWord.java

@@ -0,0 +1,115 @@
+package chelper;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import io.InputReader;
+import io.OutputWriter;
+
+public class GroupedWord {
+
+  public void solve(int testNumber, InputReader in, OutputWriter out) {
+    int n = in.nextInt();
+    String[] a = in.nextStringArray(n);
+
+    out.println(restore(a));
+  }
+
+  String restore(String[] a) {
+    List<String> list = new ArrayList<>();
+    Collections.addAll(list, a);
+
+    for (char c = 'a'; c <= 'z'; c++) {
+      List<String> interesting = new ArrayList<>();
+      for (int i = 0; i < list.size();) {
+        if (list.get(i).contains("" + c)) {
+          interesting.add(list.get(i));
+          list.remove(i);
+        } else {
+          i++;
+        }
+      }
+
+      if (interesting.isEmpty()) {
+        continue;
+      }
+
+      String result = combine(c, interesting);
+      if (result == null) {
+        return "IMPOSSIBLE";
+      }
+      list.add(result);
+    }
+
+    if (list.size() > 1) {
+      return "MANY";
+    }
+    return list.get(0);
+  }
+
+  boolean isInvalid(String s) {
+    for (int i = 0; i < s.length(); i++) {
+      for (int j = i + 1; j < s.length(); j++) {
+        if (s.charAt(i) == s.charAt(j) && s.charAt(i) != s.charAt(i + 1)) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
+  String combine(char c, List<String> interesting) {
+    List<String> only = new ArrayList<>();
+    List<String> starts = new ArrayList<>();
+    List<String> ends = new ArrayList<>();
+    List<String> middle = new ArrayList<>();
+
+    for (String s : interesting) {
+      if (isInvalid(s)) {
+        return null;
+      }
+
+      boolean doesStart = s.charAt(0) == c;
+      boolean doesEnd = s.charAt(s.length() - 1) == c;
+
+      if (doesStart) {
+        if (doesEnd) {
+          only.add(s);
+        } else {
+          starts.add(s);
+        }
+      } else {
+        if (doesEnd) {
+          ends.add(s);
+        } else {
+          middle.add(s);
+        }
+      }
+    }
+
+    if (starts.size() > 1 || ends.size() > 1 || middle.size() > 1) {
+      return null;
+    }
+
+    if (!middle.isEmpty()) {
+      if (only.isEmpty() && starts.isEmpty() && ends.isEmpty()) {
+        return middle.get(0);
+      } else {
+        return null;
+      }
+    }
+
+    StringBuilder sb = new StringBuilder();
+    for (String s : ends) {
+      sb.append(s);
+    }
+    for (String s : only) {
+      sb.append(s);
+    }
+    for (String s : starts) {
+      sb.append(s);
+    }
+    return sb.toString();
+  }
+}