牛客题目链接

1. 题目考点

1. 字符串翻转

2. 考点解析

1. 分离成数组，再翻转每个单词

public String trans(String s, int n) {
    // write code here
    String[] strs = s.split(" ");
    for (int i = 0; i < strs.length; i++) {
        String newStr = "";
        for (int j = 0; j < strs[i].length(); j++) {
            if (strs[i].charAt(j) >= 'a' && strs[i].charAt(j) <= 'z')
                newStr += (char)(strs[i].charAt(j) - 32);
            else
                newStr += (char)(strs[i].charAt(j) + 32);
        }
        strs[i] = newStr;
    }
     
    StringBuilder sb = new StringBuilder();
    if (s.charAt(s.length() - 1) == ' ') sb.append(" ");
    for (int i = strs.length - 1; i >= 0; i--) {
        sb.append(strs[i]).append(" ");
    }
    sb.delete(sb.length() - 1, sb.length());
    return sb.toString();
}

2. 两次翻转（待补充）