剑指Offer打卡day42——AcWing 77. 翻转单词顺序

Posted 2021-05-25 Johnny*

【题目描述】

AcWing 77. 翻转单词顺序

【思路】

翻转整个句子 再将句子的每个单词翻转

class Solution {
    
    public String reverseSingleWord(String s){
        char c[] = s.toCharArray();
        int n = c.length;
        for(int i = 0, j = n - 1; i <= j ; i ++, j -- ){
            char t = c[i];
            c[i] = c[j];
            c[j] = t;
        }
        return new String(c);    
        
    }
    public String reverseWords(String s) {
        String str[] = reverseSingleWord(s).split(" ");
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < str.length; i ++)
            if( i == str.length - 1) sb.append(reverseSingleWord(str[i]));
            else  sb.append(reverseSingleWord(str[i])).append(" ");
        return sb.toString();
    }
}