Create All Unique Characters II.java

All Unique Characters II.java

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+/*
+Determine if the characters of a given string are all unique.
+
+Assumptions
+We are using ASCII charset, the value of valid characters are from 0 to 255
+The given string is not null
+
+Examples
+all the characters in "abA+\8" are unique
+"abA+\a88" contains duplicate characters
+
+time = O(n)
+space = O(n)
+*/
+
+public class Solution {
+  public boolean allUnique(String word) {
+    // Write your solution here
+    int[] vec = new int[8];
+    char[] array = word.toCharArray();
+    for (char c : array) {
+    	if ((vec[c / 32] >>> (c % 32) & 1) != 0) {
+      	return false;
+      }
+      vec[c / 32] |= (1 << (c % 32));
+    }
+    return true;
+  }
+}