class Solution {
public String reverseString(String s) {
StringBuffer sb = new StringBuffer();
for(int i=s.length()-1; i >= 0; i--)
sb.append(s.charAt(i));
return sb.toString();
}
}
或者使用String.toCharArray()方法转换为字符数组之中,将数组两边交换,得到结果,这样耗费的时间大概会减少一半
class Solution {
public String reverseString(String s) {
char[] res = s.toCharArray();
int i = 0;
int j = s.length()-1;
while(i < j){
char temp = res[i];
res[i] = res[j];
res[j] = temp;
i++;
j--;
}
return new String(res);
}
}