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