Skip to content

Instantly share code, notes, and snippets.

@bknarendra
Created May 14, 2012 07:37
Show Gist options
  • Save bknarendra/2692488 to your computer and use it in GitHub Desktop.
Save bknarendra/2692488 to your computer and use it in GitHub Desktop.
Codercharts:Word Lazy swap
import java.io.*;
import java.util.*;
public class word_lazy_swap
{
public static HashSet<String>dict;
public static void main(String[] args) throws Exception
{
InputReader sc=new InputReader(new FileInputStream(args[0]));
dict=new HashSet<String>();
while(!sc.isExhausted()) dict.add(sc.readLine());
Queue<String>q=new LinkedList<String>();
sc=new InputReader(new FileInputStream(args[1]));
String st="",end="",cur="";
Set<String>used=new LinkedHashSet<String>();
HashMap<String,String>back=new HashMap<String,String>();
int flag=0,res=0;
List<String>suc;
while(!sc.isExhausted())
{
st=sc.readString();
end=sc.readString();
q.add(st);
while(!q.isEmpty())
{
cur=q.remove();
suc=successors(cur);
for(int i=0;i<suc.size();i++)
{
if(cur.equals(end))
{
flag=1;
break;
}
else
{
if(!used.contains(suc.get(i))&&!q.contains(suc.get(i)))
{
q.add(suc.get(i));
back.put(suc.get(i),cur);
used.add(cur);
}
}
}
if(flag==1) break;
}
cur=end;
while(back.get(cur)!=null)
{
cur=back.get(cur);
res++;
}
res++;
System.out.println(res);
used.clear();
back.clear();
q.clear();
res=0;flag=0;
}
}
public static LinkedList<String>successors(String cur)
{
StringBuffer sb;
LinkedList<String>suc=new LinkedList<String>();
int n=cur.length();
char ch;
for(int i=0;i<n;i++)
{
sb=new StringBuffer(cur);
ch=sb.charAt(i);
for(char j='A';j<='Z';j++)
{
if(ch!=j)
{
sb.setCharAt(i,j);
if(dict.contains(sb.toString())) suc.add(sb.toString());
sb.setCharAt(i,ch);
}
}
}
return suc;
}
}
class InputReader {
private boolean finished = false;
private InputStream stream;
private byte[] buf = new byte[1024];
private int curChar;
private int numChars;
public InputReader(InputStream stream) {
this.stream = stream;
}
public int read() {
if (numChars == -1)
throw new InputMismatchException();
if (curChar >= numChars) {
curChar = 0;
try {
numChars = stream.read(buf);
} catch (IOException e) {
throw new InputMismatchException();
}
if (numChars <= 0)
return -1;
}
return buf[curChar++];
}
public int peek() {
if (numChars == -1)
return -1;
if (curChar >= numChars) {
curChar = 0;
try {
numChars = stream.read(buf);
} catch (IOException e) {
return -1;
}
if (numChars <= 0)
return -1;
}
return buf[curChar];
}
public String readString() {
int c = read();
while (isSpaceChar(c))
c = read();
StringBuffer res = new StringBuffer();
do {
res.appendCodePoint(c);
c = read();
} while (!isSpaceChar(c));
return res.toString();
}
private boolean isSpaceChar(int c) {
return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
}
private String readLine0() {
StringBuffer buf = new StringBuffer();
int c = read();
while (c != '\n' && c != -1) {
if (c != '\r')
buf.appendCodePoint(c);
c = read();
}
return buf.toString();
}
public String readLine() {
String s = readLine0();
while (s.trim().length() == 0)
s = readLine0();
return s;
}
public String readLine(boolean ignoreEmptyLines) {
if (ignoreEmptyLines)
return readLine();
else
return readLine0();
}
public char readCharacter() {
int c = read();
while (isSpaceChar(c))
c = read();
return (char) c;
}
public boolean isExhausted() {
int value;
while (isSpaceChar(value = peek()) && value != -1)
read();
return value == -1;
}
public String next() {
return readString();
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment