Reverse String
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.
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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"]
Java Solution
Solution:
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class Solution {
public void reverseString(char[] s) {
int head = 0;
int tail = s.length - 1;
while(head < tail){
char tmp = s[head];
s[head] = s[tail];
s[tail] = tmp;
head++;
tail--;
}
}
}
