leetcode ReverseString
z
 2019-04-09 10:36:27   
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public class ReverseString {
  /**
   * 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"]
   */
  public static  void reverseString(char[] s) {
    int n = s.length;
    int left = 0;
    int right = s.length-1;
    while(left < right){
      char t = s[left];
      s[left] = s[right];
      s[right] = t;
      left ++;
      right --;
    }
    return ;
  }
  public static void main(String[] args){
    char[] s = new char[]{'h','e','l','l','0'};
    reverseString(s);
    for (char c: s){
      System.out.println(c);
    }
  }
}