Sorting the Sentence

给一个字符串, 里面的每个words都是打乱顺序的, 要求按照每个words的末尾数字重新排序.

class Solution {
    public String sortSentence(String s) {
        String[] strs = s.split(" ");
        int n = strs.length;
        Map<Integer, String> map = new HashMap<>();
        for(String ss : strs) {
            map.put(ss.charAt(ss.length() - 1) - '0', ss.substring(0, ss.length() - 1));
        }
        StringBuilder sb = new StringBuilder();
        for(int i = 1; i <= n; i++){
            sb.append(map.get(i)+' ');
        }
        return sb.toString().trim();
    }
}