题解 | #字符串变形#慎用split,会把字符串首尾的空格删除

import java.util.*;

public class Solution { public String trans(String s, int n) { // write code here String[] str = s.split(" ",-1); int left=0,right=str.length-1; while(left<right){ String tmp=str[left]; str[left] = str[right]; str[right] = tmp; left++; right--; } StringBuffer sb = new StringBuffer(); for(int i=0;i<str.length;i++){ char[] ch = str[i].toCharArray(); for(int j=0;j<ch.length;j++){ if(Character.isLowerCase(ch[j])) ch[j]=Character.toUpperCase(ch[j]); else if(Character.isUpperCase(ch[j])) ch[j]=Character.toLowerCase(ch[j]); } String m=new String(ch); sb.append(m); if(i!=str.length-1) sb.append(" "); } return sb.toString(); } }