# 344. 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**](https://en.wikipedia.org/wiki/In-place_algorithm) with O(1) extra memory.

You may assume all the characters consist of [printable ascii characters](https://en.wikipedia.org/wiki/ASCII#Printable_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"]
```

**Solution**

```
    public void reverseString(char[] s) {
        for(int i = 0; i < s.length; i++){
            int j = s.length - i - 1;
            if(i >= j){
                break;
            }else
                swap(s, i, j);
        }
    }
    
    public void swap(char[] s, int i, int j){
        if(i != j){
            char temp = s[i];
            s[i] = s[j];
            s[j] = temp;
        }
    }
```
