Notes

1111111111111
import java.util.Scanner;

public class StringPermutation {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);

System.out.print("Введите строку: ");
String inputString = scanner.nextLine();

System.out.print("Введите позицию первого символа для перестановки: ");
int position1 = scanner.nextInt();

System.out.print("Введите позицию второго символа для перестановки: ");
int position2 = scanner.nextInt();

String swappedString = swapCharacters(inputString, position1, position2);

System.out.println("Измененная строка: " + swappedString);
}

public static String swapCharacters(String inputString, int position1, int position2) {
char[] charArray = inputString.toCharArray();

char temp = charArray[position1];
charArray[position1] = charArray[position2];
charArray[position2] = temp;

return String.valueOf(charArray);
}
}
22222222222222222222222
import java.util.Scanner;

public class LongestSentence {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);

System.out.print("Введите строку: ");
String inputString = scanner.nextLine();

String longestSentence = findLongestSentence(inputString);

System.out.println("Самое длинное предложение без учета пробелов: " + longestSentence);
}

public static String findLongestSentence(String inputString) {
String[] sentences = inputString.split(".");

String longestSentence = "";
int maxLength = 0;

for (String sentence : sentences) {
String sentenceWithoutSpaces = sentence.replaceAll(" ", "");

if (sentenceWithoutSpaces.length() > maxLength) {
maxLength = sentenceWithoutSpaces.length();
longestSentence = sentenceWithoutSpaces;
}
}

return longestSentence;
}
}
3333333333333333
public class StringPermutation {
public static void main(String[] args) {
String str = "abc";
permutation(str, 0, str.length() - 1);
}

public static void permutation(String str, int left, int right) {
if (left == right) {
System.out.println(str);
} else {
for (int i = left; i <= right; i++) {
str = swapCharacters(str, left, i);
permutation(str, left + 1, right);
str = swapCharacters(str, left, i);
}
}
}

public static String swapCharacters(String str, int i, int j) {
char[] charArray = str.toCharArray();
char temp = charArray[i];
charArray[i] = charArray[j];
charArray[j] = temp;
return String.valueOf(charArray);
}
}