[Java] Java算法之串的简单处理

public class 串的简单处理 {
  public static void main(string[] args) {
  scanner scanner = new scanner(system.in);
  string string = scanner.nextline();
  vector<character> vector = new vector<character>();
  for (int i = 0; i < string.length(); i++) {
    vector.add(string.charat(i));
  }
  try {
    int index = 0;
    while (index < vector.size()) {
    //判断第一个是否为小写的英文字符，是的话进行操作
    if (index == 0 && vector.elementat(index) >= 'a'
      && vector.elementat(index) <= 'z') {
      //replaces the element at the specified position in this vector with the specified element
      vector.set(index,(char) (vector.elementat(index) - ('a' - 'a')));
    } else if (vector.elementat(index - 1) == ' '&& vector.elementat(index) == ' ') {
      //处理有多个空格的可能
      vector.remove(index);
      index--;
    } else if (vector.elementat(index - 1) == ' '
      && (vector.elementat(index) >= 'a' && vector
        .elementat(index) <= 'z')) {
      //判断是空格后边的字符
      vector.set(index,
        (char) (vector.elementat(index) - ('a' - 'a')));
    } else if ((vector.elementat(index) >= 'a' && vector
      .elementat(index) <= 'z')
      && (vector.elementat(index - 1) >= '0' && vector
        .elementat(index - 1) <= '9')) {
      vector.add(index, '_');
      index++;
    } else if ((vector.elementat(index - 1) >= 'a' && vector
      .elementat(index - 1) <= 'z')
      && (vector.elementat(index) >= '0' && vector
        .elementat(index) <= '9')) {
      //判断的是数字
      vector.add(index, '_');
      index++;
    }
    index++;
    }
    for (int i = 0; i < vector.size(); i++) {
    system.out.print(vector.elementat(i));
    }
    system.out.println();
  } catch (arrayindexoutofboundsexception e) {
  }
  }
}

public class simplestring {
  // 打印字符串的函数
  public static void print(string[] s) {
  for (int i = 0; i < s.length - 1; i++) {
    system.out.print(s[i] + " ");
  }
  system.out.println(s[s.length - 1]);
  }
  public static void main(string[] args) {
  scanner scan = new scanner(system.in);
  string s = scan.nextline();
  string[] ss = s.split("[\\s]+"); // 根据正则表达式，删除一个或多个空格,将字符串保存为字符数组
  for (int i = 0; i < ss.length; i++) {
    // 将每一个字符数组的首字母改为大写
    string up = ("" + ss[i].charat(0)).touppercase(); // 大写
    stringbuffer sb = new stringbuffer(ss[i]);
    ss[i] = sb.replace(0, 1, up).tostring();
    // 上边已经把字符串数组的首字母该为大写，然后对更改后的字符数组判断是否有数字
    matcher m = pattern.compile("\\d+").matcher(ss[i]);// 0-9出现一次或多次
    while (m.find()) {
    // m.group()：returns the input subsequence matched by the previous match
    string num = new string(m.group());
    string num2 = num;
    num2 = "_" + num + "_"; // 数字前后都添加"_"
    ss[i] = ss[i].replace(num, num2);
    if (ss[i].startswith("_")) { // 去头"_"
      ss[i] = ss[i].substring(1);
    }
    if (ss[i].endswith("_")) { // 去尾"_"
      ss[i] = ss[i].substring(0, ss[i].length() - 1);
    }
    }
  }
  print(ss);
  }
}