Day-04-Reverse String.cpp

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"]
   Hide Hint #1
The entire logic for reversing a string is based on using the opposite directional two-pointer approach!




class Solution {
public:
    void reverseString(vector<char>& s) {
        int n=s.size();
        for(int i=0,j=n-1;i<n/2;i++,j--){
            char tmp=s[i];
            s[i]=s[j];
            s[j]=tmp;
        }
    }

};