Reverse String Problem


Description

LeetCode Problem 344.

Write a function that reverses a string. The input string is given as an array of characters s.

You must do this by modifying the input array in-place with O(1) extra memory.

Example 1:

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Input: s = ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]

Example 2:

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Input: s = ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]

Constraints:

  • 1 <= s.length <= 10^5
  • s[i] is a printable ascii character.


Sample C++ Code

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class Solution {
public:
    string reverseString(string s) {
        int i = 0, j = s.size() - 1;
        while(i < j){
            swap(s[i++], s[j--]); 
        }
        return s;
    }
};




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