結果
| 問題 |
No.470 Inverse S+T Problem
|
| コンテスト | |
| ユーザー |
 tanzaku
|
| 提出日時 | 2016-12-20 00:23:45 |
| 言語 | Java (openjdk 23) |
| 結果 |
AC
|
| 実行時間 | 91 ms / 2,000 ms |
| コード長 | 8,996 bytes |
| コンパイル時間 | 5,304 ms |
| コンパイル使用メモリ | 89,100 KB |
| 実行使用メモリ | 39,896 KB |
| 最終ジャッジ日時 | 2024-12-22 13:09:19 |
| 合計ジャッジ時間 | 7,544 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge3 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 4 |
| other | AC * 27 |
ソースコード
import java.io.*;
import java.math.*;
import java.util.*;
import static java.util.Arrays.*;
public class _470 {
private static final int mod = (int)1e9+7;
final Random random = new Random(0);
final IOFast io = new IOFast();
/// MAIN CODE
public void run() throws IOException {
// int TEST_CASE = Integer.parseInt(new String(io.nextLine()).trim());
int TEST_CASE = 1;
while(TEST_CASE-- != 0) {
int n = io.nextInt();
if (n > 52) {
io.out.println("Impossible");
return;
}
Sat2 sat = new Sat2(2*n);
String[][][] cs = new String[n][2][2];
for (int i = 0; i < n; i++) {
String s = io.nextString();
cs[i][0][0] = s.substring(0, 1);
cs[i][0][1] = s.substring(1, 3);
cs[i][1][0] = s.substring(2, 3);
cs[i][1][1] = s.substring(0, 2);
sat.Or(sat.Not(2*i+0), sat.Not(2*i+1));
sat.Or(2*i+0, 2*i+1);
for (int j = 0; j < i; j++) {
for (int k = 0; k < 2; k++) {
for (int l = 0; l < 2; l++) {
if (cs[i][k][0].equals(cs[j][l][0]) || cs[i][k][1].equals(cs[j][l][1])) {
sat.Or(sat.Not(2*i+k), sat.Not(2*j+l));
// dump(i, j, k, l);
}
}
}
}
}
if (!sat.satisfy()) {
io.out.println("Impossible");
return;
}
for (int i = 0; i < n; i++) {
swap(cs[i][1], 0, 1);
}
for (int i = 0; i < 2*n; i++) {
if (sat.ans[i]) {
io.out.println(cs[i/2][i%2][0] + " " + cs[i/2][i%2][1]);
}
}
}
}
int toNum(char c) {
if (Character.isLowerCase(c)) return c - 'a';
return c - 'A' + 26;
}
static
public class Sat2 {
final int n;
final boolean[] ans;
final StronglyConnectedComponent scc;
void clear() {
scc.clear();
}
public Sat2(int n) {
this.n = n;
ans = new boolean[n];
scc = new StronglyConnectedComponent(n * 2);
}
private int Not(int a) {
if(a < 0 || a >= 2 * n) throw new RuntimeException();
return a >= n ? a - n : a + n;
}
public void Or(int a, int b) {
if(a < 0 || a >= 2 * n || b < 0 || b >= 2 * n) throw new RuntimeException();
scc.addEdge(Not(a), b);
scc.addEdge(Not(b), a);
}
public boolean satisfy() {
scc.scc();
for(int i = 0; i < n; i++) {
// 同じ強連結成分に含まれたら充足不可能
if(scc.cmp[i] == scc.cmp[i + n]) {
return false;
}
}
for(int i = 0; i < n; i++) {
ans[i] = scc.cmp[i] > scc.cmp[i + n];
}
return true;
}
static public class StronglyConnectedComponent {
int V;
List<List<Integer>> G;
List<List<Integer>> rG;
List<Integer> vs;
boolean[] used;
public int[] cmp;
void clear() {
for (int i = 0; i < V; i++) {
G.get(i).clear();
rG.get(i).clear();
}
}
public StronglyConnectedComponent(int n) {
V = n;
G = new ArrayList<List<Integer>>(n);
rG = new ArrayList<List<Integer>>(n);
vs = new ArrayList<Integer>();
used = new boolean[n];
cmp = new int[n];
for (int i = 0; i < n; i++) {
G.add(new ArrayList<Integer>());
rG.add(new ArrayList<Integer>());
}
}
public void addEdge(int from, int to) {
G.get(from).add(to);
rG.get(to).add(from);
}
private void dfs(int v) {
used[v] = true;
for (int i = 0; i < G.get(v).size(); i++)
if (!used[G.get(v).get(i)])
dfs(G.get(v).get(i));
vs.add(v);
}
private void rdfs(int v, int k) {
used[v] = true;
cmp[v] = k;
for (int i = 0; i < rG.get(v).size(); i++)
if (!used[rG.get(v).get(i)])
rdfs(rG.get(v).get(i), k);
}
public int scc() {
for (int i = 0; i < V; i++)
used[i] = false;
vs.clear();
for (int i = 0; i < V; i++)
if (!used[i])
dfs(i);
for (int i = 0; i < V; i++)
used[i] = false;
int k = 0;
for (int i = vs.size() - 1; i >= 0; i--)
if (!used[vs.get(i)])
rdfs(vs.get(i), k++);
return k;
}
}
}
/// TEMPLATE
static int gcd(int n, int r) { return r == 0 ? n : gcd(r, n%r); }
static long gcd(long n, long r) { return r == 0 ? n : gcd(r, n%r); }
static <T> void swap(T[] x, int i, int j) { T t = x[i]; x[i] = x[j]; x[j] = t; }
static void swap(int[] x, int i, int j) { int t = x[i]; x[i] = x[j]; x[j] = t; }
void printArrayLn(int[] xs) { for(int i = 0; i < xs.length; i++) io.out.print(xs[i] + (i==xs.length-1?"\n":" ")); }
void printArrayLn(long[] xs) { for(int i = 0; i < xs.length; i++) io.out.print(xs[i] + (i==xs.length-1?"\n":" ")); }
static void dump(Object... o) { System.err.println(Arrays.deepToString(o)); }
void main() throws IOException {
// IOFast.setFileIO("rle-size.in", "rle-size.out");
try { run(); }
catch (EndOfFileRuntimeException e) { }
io.out.flush();
}
public static void main(String[] args) throws IOException { new _470().main(); }
static class EndOfFileRuntimeException extends RuntimeException {
private static final long serialVersionUID = -8565341110209207657L; }
static
public class IOFast {
private InputStream in = System.in;
private PrintWriter out = new PrintWriter(System.out);
private static int pos, readLen;
private static final byte[] buffer = new byte[1024 * 8];
private static char[] str = new char[500*8*2];
private static boolean[] isDigit = new boolean[256];
private static boolean[] isSpace = new boolean[256];
private static boolean[] isLineSep = new boolean[256];
static { for(int i = 0; i < 10; i++) { isDigit['0' + i] = true; } isDigit['-'] = true; isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true; isLineSep['\r'] = isLineSep['\n'] = true; }
public byte read() throws IOException { if(pos >= readLen) { pos = 0; readLen = in.read(buffer); if(readLen <= 0) { throw new EndOfFileRuntimeException(); } } return buffer[pos++]; }
public int nextInt() throws IOException {
byte first = (byte)nextChar();
boolean minus = false;
int res = 0;
if (first == '-') {
minus = true;
} else {
res = first - '0';
}
while (true) {
byte b = read();
if (isSpace[b]) break;
res = res * 10 + b - '0';
}
return minus ? -res : res;
}
public long nextLong() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); int i = 0; long ret = 0; if(str[0] == '-') { i = 1; } for(; i < len; i++) ret = ret * 10 + str[i] - '0'; if(str[0] == '-') { ret = -ret; } return ret; }
public char nextChar() throws IOException { while(true) { final int c = read(); if(!isSpace[c]) { return (char)c; } } }
int reads(int len, boolean[] accept) throws IOException { try { while(true) { final int c = read(); if(accept[c]) { break; } if(str.length == len) { char[] rep = new char[str.length * 3 / 2]; System.arraycopy(str, 0, rep, 0, str.length); str = rep; } str[len++] = (char)c; } } catch(EndOfFileRuntimeException e) { ; } return len; }
int reads(char[] cs, int len, boolean[] accept) throws IOException { try { while(true) { final int c = read(); if(accept[c]) { break; } cs[len++] = (char)c; } } catch(EndOfFileRuntimeException e) { ; } return len; }
public char[] nextLine() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isLineSep); try { if(str[len-1] == '\r') { len--; read(); } } catch(EndOfFileRuntimeException e) { ; } return Arrays.copyOf(str, len); }
public String nextString() throws IOException { return new String(next()); }
public char[] next() throws IOException { int len = 0; str[len++] = nextChar(); len = reads(len, isSpace); return Arrays.copyOf(str, len); }
// public int next(char[] cs) throws IOException { int len = 0; cs[len++] = nextChar(); len = reads(cs, len, isSpace); return len; }
// public double nextDouble() throws IOException { return Double.parseDouble(nextString()); }
public double nextDouble() throws IOException {
double res = nextChar() - '0';
while (true) {
byte c = read();
if (isSpace[c]) return res;
if (c == '.') break;
res = res * 10 + c - '0';
}
double d = 1;
while (true) {
byte c = read();
// dump(c);
if (!isDigit[c]) break;
res = res * 10 + c - '0';
d *= 10;
}
// dump(1);
return res / d;
}
public long[] nextLongArray(final int n) throws IOException { final long[] res = new long[n]; for(int i = 0; i < n; i++) { res[i] = nextLong(); } return res; }
public int[] nextIntArray(final int n) throws IOException { final int[] res = new int[n]; for(int i = 0; i < n; i++) { res[i] = nextInt(); } return res; }
public int[][] nextIntArray2D(final int n, final int k) throws IOException { final int[][] res = new int[n][]; for(int i = 0; i < n; i++) { res[i] = nextIntArray(k); } return res; }
public int[][] nextIntArray2DWithIndex(final int n, final int k) throws IOException { final int[][] res = new int[n][k+1]; for(int i = 0; i < n; i++) { for(int j = 0; j < k; j++) { res[i][j] = nextInt(); } res[i][k] = i; } return res; }
public double[] nextDoubleArray(final int n) throws IOException { final double[] res = new double[n]; for(int i = 0; i < n; i++) { res[i] = nextDouble(); } return res; }
}
}