编写一个程序对字符串结构进行增删改查操作java顺序串

以下是一个简单的Java顺序串类，包含了基本的增删改查操作：

public class SeqString {
    private char[] data;
    private int length;

    public SeqString() {
        data = new char[0];
        length = 0;
    }

    public SeqString(String str) {
        data = str.toCharArray();
        length = str.length();
    }

    public SeqString(char[] arr) {
        data = arr.clone();
        length = arr.length;
    }

    public int length() {
        return length;
    }

    public char charAt(int index) {
        if (index < 0 || index >= length) {
            throw new IndexOutOfBoundsException("Index out of range: " + index);
        }
        return data[index];
    }

    public SeqString substring(int beginIndex, int endIndex) {
        if (beginIndex < 0 || endIndex > length || beginIndex > endIndex) {
            throw new IndexOutOfBoundsException("Index out of range: " + beginIndex + ", " + endIndex);
        }
        char[] newData = new char[endIndex - beginIndex];
        System.arraycopy(data, beginIndex, newData, 0, endIndex - beginIndex);
        return new SeqString(newData);
    }

    public SeqString insert(int offset, String str) {
        if (offset < 0 || offset > length) {
            throw new IndexOutOfBoundsException("Index out of range: " + offset);
        }
        char[] newData = new char[length + str.length()];
        System.arraycopy(data, 0, newData, 0, offset);
        System.arraycopy(str.toCharArray(), 0, newData, offset, str.length());
        System.arraycopy(data, offset, newData, offset + str.length(), length - offset);
        return new SeqString(newData);
    }

    public SeqString delete(int offset, int len) {
        if (offset < 0 || offset + len > length) {
            throw new IndexOutOfBoundsException("Index out of range: " + offset + ", " + len);
        }
        char[] newData = new char[length - len];
        System.arraycopy(data, 0, newData, 0, offset);
        System.arraycopy(data, offset + len, newData, offset, length - offset - len);
        return new SeqString(newData);
    }

    public SeqString replace(String oldStr, String newStr) {
        int index = indexOf(oldStr);
        if (index == -1) {
            return this;
        }
        SeqString prefix = substring(0, index);
        SeqString suffix = substring(index + oldStr.length(), length);
        return prefix.concat(newStr).concat(suffix.replace(oldStr, newStr));
    }

    public int indexOf(String str) {
        int maxIndex = length - str.length();
        for (int i = 0; i <= maxIndex; i++) {
            boolean match = true;
            for (int j = 0; j < str.length(); j++) {
                if (data[i + j] != str.charAt(j)) {
                    match = false;
                    break;
                }
            }
            if (match) {
                return i;
            }
        }
        return -1;
    }

    public SeqString concat(String str) {
        return insert(length, str);
    }

    @Override
    public String toString() {
        return new String(data);
    }
}

使用示例：

SeqString str = new SeqString("hello");
System.out.println(str); // hello
System.out.println(str.charAt(1)); // e
System.out.println(str.substring(1, 4)); // ell
System.out.println(str.insert(3, "world")); // helworldlo
System.out.println(str.delete(2, 3)); // hewlo
System.out.println(str.replace("ew", "l")); // hllo
System.out.println(str.indexOf("l")); // 2
System.out.println(str.concat("world")); // helloworld