Given two strings s and t , write a function to determine if t is an anagram of s.
Example 1:
Input: s = "anagram", t = "nagaram" Output: true
Example 2:
Input: s = "rat", t = "car" Output: false
Note: You may assume the string contains only lowercase alphabets.
Follow up: What if the inputs contain unicode characters? How would you adapt your solution to such case?
分析¶
确认错位词。可以使用两种方法,都非常简单
- 将字符串中的字符排序,然后一一比较字符是否相等
- 将字符串中的字符放到哈希表中分类计数,其中一个+1,另一个-1,最后都要等于0
public boolean isAnagram(String s, String t) { if (s.length() != t.length()) return false; char[] sChar = s.toCharArray(), tChar = t.toCharArray(); Arrays.sort(sChar); Arrays.sort(tChar); return Arrays.equals(sChar, tChar); }
利用哈希表分类计数:
public boolean isAnagram(String s, String t) { if (s.length() != t.length()) return false; // 一共只有26个字母 int[] count = new int[26]; for (int i = 0; i < s.length(); i++) { count[s.charAt(i) - 'a']++; count[t.charAt(i) - 'a']--; } for (int num : count) if (num != 0) return false; return true; }
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