Write a function that reverses a string. The input string is given as an array of characters char[].
Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
You may assume all the characters consist of printable ascii characters.
Example 1:
Input: ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]
Example 2:
Input: ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]
class Solution {
public void reverseString(char[] s) {
int i=0, j=s.length-1;
while(i<s.length/2){
char temp = s[i];
s[i++] = s[j];
s[j--] = temp;
}
}
}class Solution {
public String reverseString(String s) {
return new StringBuilder(s).reverse().toString();
}
}