TestString.java

public class TestString {

    public static void main(String... args) {
        final String word = "timecomplexityn";
        System.out.println(word);
        final String space = " ".repeat(word.length()-2);
        for(int i = 1; i < word.length() - 1; i++) {
            System.out.print(word.charAt(i) + space + word.charAt(word.length() - i) + "\n");
        }
        System.out.println(new StringBuilder(word).reverse());
    }
}