cc150

Solution.java

/**
 * created by howie zhang
 * 2015/3/31
 * cc150 1.1
 */
public class Solution {
    public boolean isUnique(String s) {
        if (s.length() > 256)
            return false;
        boolean[] all = new boolean[256];
        for (int i = 0; i < s.length(); i++) {
            int pos = s.charAt(i);
            if (all[pos])
                return false;
            else
                all[pos] = true;
        }
        return true;
    }
}