StringBuilderWithDeque.java

import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Deque;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

public class StringBuilderWithDeque {

    public static void main(String[] args) {

        long start, end;

        int MAX_STR = Integer.parseInt(args[0]);
        System.out.println("MAX_STR = " + MAX_STR);

        StringBuilder build1 = new StringBuilder();
        start = System.currentTimeMillis();
        IntStream.range(0, MAX_STR)
                .sequential()
                .forEach(i -> build1.append(Integer.toString(i)));
        String build1Out = build1.toString();
        end = System.currentTimeMillis();

        System.out.println("Final length = " + build1Out.length());
//        System.out.println(build1Out.toString());
        System.out.println("Case 1 : " + (end-start)/1000.0 + " sec");

        StringBuilder build2 = new StringBuilder();
        start = System.currentTimeMillis();
        IntStream.range(0, MAX_STR)
                .sequential()
                .forEach(i -> build2.insert(0, Integer.toString(i)));
        String build2Out = build2.toString();
        end = System.currentTimeMillis();

//        System.out.println(build2Out.toString());
        System.out.println("Case 2 : " + (end-start)/1000.0 + " sec");


        StringBuilder build3 = new StringBuilder();
        start = System.currentTimeMillis();
        IntStream.range(0, MAX_STR)
                .sequential()
                .forEach(i -> {
                    if (i%2 == 0) build3.append(Integer.toString(i)); else build3.insert(0, Integer.toString(i));
                });
        String build3Out = build3.toString();
        end = System.currentTimeMillis();

//        System.out.println(b3Out.toString());
        System.out.println("Case 3 : " + (end-start)/1000.0 + " sec");


        start = System.currentTimeMillis();
        List<String> inorderList = new ArrayList<>();
        IntStream.range(0, MAX_STR)
                .sequential()
                .forEach(i -> inorderList.add(Integer.toString(i)));
        String listOut = inorderList.stream().collect(Collectors.joining(""));
        end = System.currentTimeMillis();

//        System.out.println(listOut.toString());
        System.out.println("Case 4 : " + (end-start)/1000.0 + " sec");


        start = System.currentTimeMillis();
        Deque<String> deque = new ArrayDeque<>();
        IntStream.range(0, MAX_STR)
                .sequential()
                .forEach(i -> {
                    if (i%2 == 0) deque.addLast(Integer.toString(i)); else deque.addFirst(Integer.toString(i));
                });

        String dequeOut = deque.stream().collect(Collectors.joining(""));
        end = System.currentTimeMillis();

//        System.out.println(dequeOut.toString());
        System.out.println("Case 5 : " + (end-start)/1000.0 + " sec");
    }
}

/**
 *
 * Outputs from different sample array sizes.
 *

 MAX_STR = 1000
 Final length = 2890
 Case 1 : 0.087 sec
 Case 2 : 0.002 sec
 Case 3 : 0.002 sec
 Case 4 : 0.008 sec
 Case 5 : 0.002 sec


 MAX_STR = 5000
 Final length = 18890
 Case 1 : 0.084 sec
 Case 2 : 0.007 sec
 Case 3 : 0.005 sec
 Case 4 : 0.012 sec
 Case 5 : 0.004 sec


 MAX_STR = 10000
 Final length = 38890
 Case 1 : 0.082 sec
 Case 2 : 0.025 sec
 Case 3 : 0.018 sec
 Case 4 : 0.031 sec
 Case 5 : 0.006 sec


 MAX_STR = 20000
 Final length = 88890
 Case 1 : 0.086 sec
 Case 2 : 0.09 sec
 Case 3 : 0.046 sec
 Case 4 : 0.023 sec
 Case 5 : 0.01 sec


 MAX_STR = 50000
 Final length = 238890
 Case 1 : 0.094 sec
 Case 2 : 0.668 sec
 Case 3 : 0.345 sec
 Case 4 : 0.034 sec
 Case 5 : 0.019 sec


 MAX_STR = 100000
 Final length = 488890
 Case 1 : 0.111 sec
 Case 2 : 3.058 sec
 Case 3 : 1.498 sec
 Case 4 : 0.049 sec
 Case 5 : 0.026 sec


 MAX_STR = 200000
 Final length = 1088890
 Case 1 : 0.123 sec
 Case 2 : 13.394 sec
 Case 3 : 6.714 sec
 Case 4 : 0.272 sec
 Case 5 : 0.029 sec


 MAX_STR = 500000
 Final length = 2888890
 Case 1 : 0.153 sec
 Case 2 : 127.874 sec
 Case 3 : 65.331 sec
 Case 4 : 0.461 sec
 Case 5 : 0.181 sec

 *
 */