package string;

import java.util.concurrent.atomic.AtomicReference;

import java.util.stream.IntStream;

import java.util.stream.Stream;

import static java.util.stream.Collectors.joining;

public class Question24 {

public static void main(String[] args) {

System.out.println(reverseStringLambda("Hello World"));

System.out.println(reverseStringLambdaSplitDecrement("Hello World"));

System.out.println(reverseStringLambdaSplitIncrement("Hello World"));

}

private static String reverseStringLambda(String word) {

return Stream.iterate((word.length() - 1), Question24::decrement).limit(word.length())

.map(index -> String.valueOf(word.charAt(index)))

.collect(joining());

}

private static String reverseStringLambdaSplitDecrement(String word) {

final String[] splitArray = word.split("");

return Stream.iterate((word.length() - 1), Question24::decrement).limit(word.length())

.map(index -> splitArray[index])

.collect(joining());

}

public static String reverseStringLambdaSplitIncrement(String word) {

AtomicReference<String> output = new AtomicReference<>("");

IntStream.range(0,word.length()).forEach(index-> output.set(word.charAt(index)+ output.get()));

return output.get();

}

private static String reverseStringWithoutLambdaDecrement(final String word) {

String output = "";

for(int i=word.length()-1;i>0;i--) {

output += word.charAt(i);

}

return output;

}

private static String reverseStringWithoutLambdaSplitIncrement(String word) {

String output = "";

for (int i=0;i<word.length();i++){

output = word.charAt(i)+output;

}

return output;

}

private static Integer decrement(Integer index) {

return index - 1;

}

}