Today I have done leetcode's April LeetCoding Challenge with cpp.

April LeetCoding Challenge 31

Description

Reverse String

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:

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

Example 2:

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.

Solution

auto speedup = [](){
  cin.tie(nullptr);
  cout.tie(nullptr);
  ios::sync_with_stdio(false);
  return 0;
}();
class Solution {
public:
  void reverseString(vector<char>& s) {
    int len = s.size();
    for(int i = 0; i * 2 < len; ++i) {
      swap(s[i], s[len - 1 - i]);
    }
  }
};

// Accepted
// 477/477 cases passed (20 ms)
// Your runtime beats 89.9 % of cpp submissions
// Your memory usage beats 41.72 % of cpp submissions (23.3 MB)