151. Reverse Words in a String

1.問題

2.想法

3.程式碼

class Solution {
public:
    string reverseWords(string s) {
        if (s.empty()) {
            return s;
        }
        
        int size = s.length(), last = 0, cur = 0;
        vector<string> res;
        for(int i = 0 ; i < size; i++) {
            if (s[i] == ' ') {
                if (!s.substr(last, i - last).empty()) {
                    res.push_back(s.substr(last, i - last));
                }
                last = i+ 1;
            }
        }
        if (!s.substr(last, size).empty()) {
            res.push_back(s.substr(last, size));
        }
        
        string ss = "";
        for(int i = res.size() - 1 ; i > 0; i--) {
            ss = ss + res[i] + " ";
        }
        if (!res.empty()) {
            ss += res[0];
        }
        
        return ss;
    }
};