cc150-1.2

gistfile1.java

package ch1;

/*
1.2 Implement a function void reverse(char* str) in C or C++ which reverses a nullterminated string.

* We used a temp variable to exchange the i character with leng-1-i character
* One way to do this is our method
* char[] chars = str.toCharArray();
* String newStr = String.valueOf(chars);
* 
* We can also use Stringbuilder to change a character in a string
* StringBuilder myName = new StringBuilder("domanokz");
* myName.setCharAt(4, 'x');

 Time Complexity O(n) Space O(1)
 
*/

public class ReverseString {
	
	public static String reverse(String str) {
		char temp;
		char[] chars = str.toCharArray();
		
		for(int i=0; i<str.length()/2; i++) {
			temp = chars[i];
			chars[i] = chars[str.length()-1-i];
			chars[str.length()-1-i] = temp;
		}
		return String.valueOf(chars);
	}

	public static void main(String[] args) {
		String test = "abcdef";
		test = reverse(test);
		
		System.out.println(test);	
	}

}