题解 | #字符串变形#

class Solution {
public:
    string trans(string s, int n) {
        // write code here
        // 两次翻转
        reverse(s.begin(), s.end());
        for(int i = 0; i < n; i++) {
            int j = i;
            while(s[i] != '\0' && s[i] != ' ') {
                if('a' <= s[i] && s[i] <= 'z')
                    s[i] = 'A' + s[i] - 'a';
                else if('A' <= s[i] && s[i] <= 'Z')
                    s[i] = 'a' + s[i] - 'A';
                i++;
            }
            reverse(s.begin() + j, s.begin() + i);
        }
        return s;
    }
};