c++
class Solution {
public:
string reverseString(string s) {
if (s.empty() || s.size() < 2)
return s;
int i = 0;
int j = s.size() - 1;
while (i < j) {
auto tmp = s[i];
s[i] = s[j];
s[j] = tmp;
++i;
--j;
}
return s;
}
};
python
class Solution(object):
def reverseString(self, s):
"""
:type s: str
:rtype: str
"""
s = list(s)
i, j = 0, len(s)-1
while i<j:
s[i], s[j] = s[j], s[i]
i += 1
j -= 1
return ''.join(s)