結果
| 問題 |
No.470 Inverse S+T Problem
|
| コンテスト | |
| ユーザー |
 uwi
|
| 提出日時 | 2016-12-21 19:36:03 |
| 言語 | Java (openjdk 23) |
| 結果 |
AC
|
| 実行時間 | 108 ms / 2,000 ms |
| コード長 | 6,229 bytes |
| コンパイル時間 | 5,107 ms |
| コンパイル使用メモリ | 87,480 KB |
| 実行使用メモリ | 41,288 KB |
| 最終ジャッジ日時 | 2024-12-22 13:35:29 |
| 合計ジャッジ時間 | 8,097 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge1 |
（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
package adv2016;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
public class N470_2 {
InputStream is;
PrintWriter out;
String INPUT = "";
void solve()
{
int n = ni();
char[][] u = new char[n][];
for(int i = 0;i < n;i++){
u[i] = ns(3);
}
if(n > 52){
out.println("Impossible");
return;
}
int[] from = new int[n*n*4];
int[] to = new int[n*n*4];
int p = 0;
for(int i = 0;i < n;i++){
for(int j = i+1;j < n;j++){
for(int k = 0;k < 2;k++){
for(int l = 0;l < 2;l++){
int indk = k == 0 ? 0 : 2;
int indl = l == 0 ? 0 : 2;
int iind = k == 0 ? i : i+n;
int iindi = 2*i+n-iind;
int jind = l == 0 ? j : j+n;
int jindi = 2*j+n-jind;
int xk = k == 0 ? 1 : 0;
int xl = l == 0 ? 1 : 0;
if(u[i][indk] == u[j][indl] || u[i][xk] == u[j][xl] && u[i][xk+1] == u[j][xl+1]){
from[p] = iind; to[p] = jindi; p++;
from[p] = jind; to[p] = iindi; p++;
}
}
}
}
}
int[][] g = packD(2*n, from, to, p);
int[] sign = restore2SAT(g);
if(sign == null){
out.println("Impossible");
return;
}
for(int i = 0;i < n;i++){
if(sign[i] == 1){
out.println(u[i][0] + " " + u[i][1] + u[i][2]);
}else{
out.println("" + u[i][0] + u[i][1] + " " + u[i][2]);
}
}
}
public static int[] restore2SAT(int[][] g)
{
assert g.length % 2 == 0;
int n = g.length/2;
int[] clus = decomposeToSCC(g);
int[] ret = new int[n];
for(int i = 0;i < n;i++){
if(clus[i] == clus[i+n])return null; // unsatisfied
ret[i] = clus[i] > clus[i+n] ? -1 : 1;
}
return ret;
}
public static int[] decomposeToSCC(int[][] g)
{
int n = g.length;
int[] stack = new int[n+1];
int[] ind = new int[n+1];
int[] ord = new int[n];
Arrays.fill(ord, -1);
int[] low = new int[n];
Arrays.fill(low, -1);
int sp = 0;
int id = 0; // preorder
int[] clus = new int[n];
int cid = 0;
int[] cstack = new int[n+1];
int csp = 0;
boolean[] incstack = new boolean[n];
for(int i = 0;i < n;i++){
if(ord[i] == -1){
ind[sp] = 0;
cstack[csp++] = i;
stack[sp++] = i;
incstack[i] = true;
while(sp > 0){
int cur = stack[sp-1];
if(ind[sp-1] == 0){
ord[cur] = low[cur] = id++;
}
if(ind[sp-1] < g[cur].length){
int nex = g[cur][ind[sp-1]];
if(ord[nex] == -1){
ind[sp-1]++;
ind[sp] = 0;
incstack[nex] = true;
cstack[csp++] = nex;
stack[sp++] = nex;
}else{
// shortcut
// U.tr(cur, nex, incstack[nex], low[nex], stack);
if(incstack[nex])low[cur] = Math.min(low[cur], low[nex]);
ind[sp-1]++;
}
}else{
if(ord[cur] == low[cur]){
while(csp > 0){
incstack[cstack[csp-1]] = false;
clus[cstack[--csp]] = cid;
if(cstack[csp] == cur)break;
}
cid++;
}
if(--sp >= 1)low[stack[sp-1]] = Math.min(low[stack[sp-1]], low[stack[sp]]);
}
}
}
}
return clus;
}
public static int[][] packD(int n, int[] from, int[] to){ return packD(n, from, to, from.length);}
public static int[][] packD(int n, int[] from, int[] to, int sup)
{
int[][] g = new int[n][];
int[] p = new int[n];
for(int i = 0;i < sup;i++)p[from[i]]++;
for(int i = 0;i < n;i++)g[i] = new int[p[i]];
for(int i = 0;i < sup;i++){
g[from[i]][--p[from[i]]] = to[i];
}
return g;
}
void run() throws Exception
{
is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
out = new PrintWriter(System.out);
long s = System.currentTimeMillis();
solve();
out.flush();
if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
// Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){
// @Override
// public void run() {
// long s = System.currentTimeMillis();
// solve();
// out.flush();
// if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
// }
// };
// t.start();
// t.join();
}
public static void main(String[] args) throws Exception { new N470_2().run(); }
private byte[] inbuf = new byte[1024];
public int lenbuf = 0, ptrbuf = 0;
private int readByte()
{
if(lenbuf == -1)throw new InputMismatchException();
if(ptrbuf >= lenbuf){
ptrbuf = 0;
try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
if(lenbuf <= 0)return -1;
}
return inbuf[ptrbuf++];
}
private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
private double nd() { return Double.parseDouble(ns()); }
private char nc() { return (char)skip(); }
private String ns()
{
int b = skip();
StringBuilder sb = new StringBuilder();
while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
sb.appendCodePoint(b);
b = readByte();
}
return sb.toString();
}
private char[] ns(int n)
{
char[] buf = new char[n];
int b = skip(), p = 0;
while(p < n && !(isSpaceChar(b))){
buf[p++] = (char)b;
b = readByte();
}
return n == p ? buf : Arrays.copyOf(buf, p);
}
private int[] na(int n)
{
int[] a = new int[n];
for(int i = 0;i < n;i++)a[i] = ni();
return a;
}
private long[] nal(int n)
{
long[] a = new long[n];
for(int i = 0;i < n;i++)a[i] = nl();
return a;
}
private char[][] nm(int n, int m) {
char[][] map = new char[n][];
for(int i = 0;i < n;i++)map[i] = ns(m);
return map;
}
private int[][] nmi(int n, int m) {
int[][] map = new int[n][];
for(int i = 0;i < n;i++)map[i] = na(m);
return map;
}
private int ni() { return (int)nl(); }
private long nl()
{
long num = 0;
int b;
boolean minus = false;
while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
if(b == '-'){
minus = true;
b = readByte();
}
while(true){
if(b >= '0' && b <= '9'){
num = num * 10 + (b - '0');
}else{
return minus ? -num : num;
}
b = readByte();
}
}
private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}