Topcoder--SRM144 div1
Problem Statement | |||||||||||||
| Let's say you have a binary string such as the following: 011100011 One way to encrypt this string is to add to each digit the sum of its adjacent digits. For example, the above string would become: 123210122 In particular, if P is the original string, and Q is the encrypted string, then Q[i] = P[i-1] + P[i] + P[i+1] for all digit positions i. Characters off the left and right edges of the string are treated as zeroes. An encrypted string given to you in this format can be decoded as follows (using 123210122 as an example):
Now we repeat the process, assuming the opposite about P[0]:
Note that this algorithm produces at most two decodings for any given encrypted string. There can never be more than one possible way to decode a string once the first binary digit is set. Given a String message, containing the encrypted string, return a String[] with exactly two elements. The first element should contain the decrypted string assuming the first character is '0'; the second element should assume the first character is '1'. If one of the tests fails, return the string "NONE" in its place. For the above example, you should return {"011100011", "NONE"}. | |||||||||||||
Definition | |||||||||||||
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Constraints | |||||||||||||
| - | message will contain between 1 and 50 characters, inclusive. | ||||||||||||
| - | Each character in message will be either '0', '1', '2', or '3'. | ||||||||||||
Examples | |||||||||||||
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This problem statement is the exclusive and proprietary property of TopCoder, Inc. Any unauthorized use or reproduction of this information without the prior written consent of TopCoder, Inc. is strictly prohibited. (c)2003, TopCoder, Inc. All rights reserved.
import java.util.*;
import java.util.regex.*;
import java.text.*;
import java.math.*;
import java.awt.geom.*;
public class BinaryCode
{
public String[] decode(String message)
{
String result1 = decode(message,0);
String result2 = decode(message,1);
String[] answer = new String[2];
answer[0] = result1;
answer[1] = result2;
return answer;
}
private String decode(String message, int first_value){
String result = null;
int size = message.length();
int P[] = new int[size];
int Q[] = new int[size];
char[] result_char = new char[size];
byte message_byte[] = message.getBytes();
for(int i = 0; i < size; i ++){
Q[i] = message_byte[i] - (byte)'0';
}
P[0] = first_value;
boolean flag = false;
for(int i = 0; i < size; i ++){
if(i == 0 && i == size - 1){
if(first_value == Q[0] && first_value >= 0 && first_value <= 3){
return message;
}else{
return "NONE";
}
}
if(i == 0){
P[i+1] = Q[i] - P[i];
}else if(i < size - 1){
P[i+1] = Q[i] - P[i] - P[i-1];
}
if(i < size - 1){
if(P[i+1] > 3 || P[i+1] < 0){
//flag = false;
break;
}else{
continue;
}
}
if(i == size -1){
if(Q[i] == P[i] + P[i-1]){
flag = true;
}
}
}
if(flag){
for(int i = 0; i < size; i ++){
result_char[i] = (char)(P[i] + '0');
}
result = new String(result_char);
}else{
result = "NONE";
}
return result;
}
}
//Powered by [KawigiEdit] 2.0!
public static void main(String[] args)
{
long time;
String[] answer;
boolean errors = false;
String[] desiredAnswer;
boolean same;
<%:start-tests%>
time = System.currentTimeMillis();
answer = new BinaryCode().decode("123210122");
System.out.println("Time: " + (System.currentTimeMillis()-time)/1000.0 + " seconds");
desiredAnswer = new String[]{ "011100011", "NONE" };
System.out.println("Your answer:");
if (answer.length > 0)
{
System.out.print("\t{ \"" + answer[0] + "\"");
for (int i=1; i<answer.length; i++)
System.out.print(",\n\t \"" + answer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
System.out.println("Desired answer:");
if (desiredAnswer.length > 0)
{
System.out.print("\t{ \"" + desiredAnswer[0] + "\"");
for (int i=1; i<desiredAnswer.length; i++)
System.out.print(",\n\t \"" + desiredAnswer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
same = desiredAnswer.length == answer.length;
for (int i=0; i<answer.length && same; i++)
if (!answer[i].equals(desiredAnswer[i]))
same = false;
if (!same)
{
errors = true;
System.out.println("DOESN'T MATCH!!!!");
}
else
System.out.println("Match :-)");
System.out.println();
time = System.currentTimeMillis();
answer = new BinaryCode().decode("11");
System.out.println("Time: " + (System.currentTimeMillis()-time)/1000.0 + " seconds");
desiredAnswer = new String[]{ "01", "10" };
System.out.println("Your answer:");
if (answer.length > 0)
{
System.out.print("\t{ \"" + answer[0] + "\"");
for (int i=1; i<answer.length; i++)
System.out.print(",\n\t \"" + answer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
System.out.println("Desired answer:");
if (desiredAnswer.length > 0)
{
System.out.print("\t{ \"" + desiredAnswer[0] + "\"");
for (int i=1; i<desiredAnswer.length; i++)
System.out.print(",\n\t \"" + desiredAnswer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
same = desiredAnswer.length == answer.length;
for (int i=0; i<answer.length && same; i++)
if (!answer[i].equals(desiredAnswer[i]))
same = false;
if (!same)
{
errors = true;
System.out.println("DOESN'T MATCH!!!!");
}
else
System.out.println("Match :-)");
System.out.println();
time = System.currentTimeMillis();
answer = new BinaryCode().decode("22111");
System.out.println("Time: " + (System.currentTimeMillis()-time)/1000.0 + " seconds");
desiredAnswer = new String[]{ "NONE", "11001" };
System.out.println("Your answer:");
if (answer.length > 0)
{
System.out.print("\t{ \"" + answer[0] + "\"");
for (int i=1; i<answer.length; i++)
System.out.print(",\n\t \"" + answer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
System.out.println("Desired answer:");
if (desiredAnswer.length > 0)
{
System.out.print("\t{ \"" + desiredAnswer[0] + "\"");
for (int i=1; i<desiredAnswer.length; i++)
System.out.print(",\n\t \"" + desiredAnswer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
same = desiredAnswer.length == answer.length;
for (int i=0; i<answer.length && same; i++)
if (!answer[i].equals(desiredAnswer[i]))
same = false;
if (!same)
{
errors = true;
System.out.println("DOESN'T MATCH!!!!");
}
else
System.out.println("Match :-)");
System.out.println();
time = System.currentTimeMillis();
answer = new BinaryCode().decode("123210120");
System.out.println("Time: " + (System.currentTimeMillis()-time)/1000.0 + " seconds");
desiredAnswer = new String[]{ "NONE", "NONE" };
System.out.println("Your answer:");
if (answer.length > 0)
{
System.out.print("\t{ \"" + answer[0] + "\"");
for (int i=1; i<answer.length; i++)
System.out.print(",\n\t \"" + answer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
System.out.println("Desired answer:");
if (desiredAnswer.length > 0)
{
System.out.print("\t{ \"" + desiredAnswer[0] + "\"");
for (int i=1; i<desiredAnswer.length; i++)
System.out.print(",\n\t \"" + desiredAnswer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
same = desiredAnswer.length == answer.length;
for (int i=0; i<answer.length && same; i++)
if (!answer[i].equals(desiredAnswer[i]))
same = false;
if (!same)
{
errors = true;
System.out.println("DOESN'T MATCH!!!!");
}
else
System.out.println("Match :-)");
System.out.println();
time = System.currentTimeMillis();
answer = new BinaryCode().decode("3");
System.out.println("Time: " + (System.currentTimeMillis()-time)/1000.0 + " seconds");
desiredAnswer = new String[]{ "NONE", "NONE" };
System.out.println("Your answer:");
if (answer.length > 0)
{
System.out.print("\t{ \"" + answer[0] + "\"");
for (int i=1; i<answer.length; i++)
System.out.print(",\n\t \"" + answer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
System.out.println("Desired answer:");
if (desiredAnswer.length > 0)
{
System.out.print("\t{ \"" + desiredAnswer[0] + "\"");
for (int i=1; i<desiredAnswer.length; i++)
System.out.print(",\n\t \"" + desiredAnswer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
same = desiredAnswer.length == answer.length;
for (int i=0; i<answer.length && same; i++)
if (!answer[i].equals(desiredAnswer[i]))
same = false;
if (!same)
{
errors = true;
System.out.println("DOESN'T MATCH!!!!");
}
else
System.out.println("Match :-)");
System.out.println();
time = System.currentTimeMillis();
answer = new BinaryCode().decode("12221112222221112221111111112221111");
System.out.println("Time: " + (System.currentTimeMillis()-time)/1000.0 + " seconds");
desiredAnswer = new String[]{ "01101001101101001101001001001101001", "10110010110110010110010010010110010" };
System.out.println("Your answer:");
if (answer.length > 0)
{
System.out.print("\t{ \"" + answer[0] + "\"");
for (int i=1; i<answer.length; i++)
System.out.print(",\n\t \"" + answer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
System.out.println("Desired answer:");
if (desiredAnswer.length > 0)
{
System.out.print("\t{ \"" + desiredAnswer[0] + "\"");
for (int i=1; i<desiredAnswer.length; i++)
System.out.print(",\n\t \"" + desiredAnswer[i] + "\"");
System.out.println(" }");
}
else
System.out.println("\t{ }");
same = desiredAnswer.length == answer.length;
for (int i=0; i<answer.length && same; i++)
if (!answer[i].equals(desiredAnswer[i]))
same = false;
if (!same)
{
errors = true;
System.out.println("DOESN'T MATCH!!!!");
}
else
System.out.println("Match :-)");
System.out.println();
<%:end-tests%>
if (errors)
System.out.println("Some of the test cases had errors :-(");
else
System.out.println("You're a stud (at least on the test data)! :-D ");
}