题解 | #字符串变形#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param s string字符串
     * @param n int整型
     * @return string字符串
     */
    public String trans (String s, int n) {
        String[] tmp = s.split(" ", -1);
        StringBuilder stringBuilder = new StringBuilder();
        for (int i = tmp.length - 1; i >= 0; i--) {
            stringBuilder.append(toLowerCase(tmp[i]));
            if (i != 0) {
                stringBuilder.append(" ");
            }
        }
        return stringBuilder.toString();

    }

    public static String toLowerCase( String string ) {
        string = string.trim();
        StringBuilder sb = new StringBuilder();

        for ( int i = 0; i < string.length(); i++ ) {
            String sss = String.valueOf( string.charAt( i ) );
            //判断sss是大写字母还是小写字母
            if ( sss.matches( "[A-Z]" ) ) {
                sss = sss.toLowerCase();
            } else if ( sss.matches( "[a-z]" ) ) {
                sss = sss.toUpperCase();
            } else {
                System.out.println( "其他" );
            }
            sb.append( sss );
        }
        return sb.toString();
    }

}