Question.java

package Question1_3;

import CareerCupLibrary.*;

public class Question {

	public static void removeDuplicates(char[] str) {
		if (str == null) {
			return;
		}
		int len = str.length;
		if (len < 2) {
			return;
		}
		int tail = 1;
		
		for (int i = 1; i < len; ++i) {
			int j;
			for (j = 0; j < tail; ++j)
				if (str[i] == str[j]) {
					break;
				}
			if (j == tail) {
				str[tail] = str[i];
				++tail;
			}
		}
		str[tail] = 0;
	} 
	
	public static void removeDuplicatesEff(char[] str) {
		if (str == null) return;
		int len = str.length;
		if (len < 2) return;

		boolean[] hit = new boolean[256];
		for (int i = 0; i < 256; ++i) {
			hit[i] = false;
		}
		hit[str[0]] = true;

		int tail = 1;
		for (int i = 1; i < len; ++i) {
			if (!hit[str[i]]) {
				str[tail] = str[i];
				++tail;
				hit[str[i]] = true;
			}
		}
		str[tail] = 0;
	}
	
	public static void main(String[] args) {
		String s = "helloiloveyou";
		char[] arr = s.toCharArray();
		removeDuplicatesEff(arr);
		System.out.print(AssortedMethods.charArrayToString(arr));
	}

}