[leetcode] 242. Valid Anagram

Description

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

题目的意思是：判断字符串s和t是否是相同字母异序词。

• 这道题我想的是hash表的方式，空间复杂度稍稍高了点；另一种解法是用了一个大小为26的一维数组，统计每个字符的频率就行了。

代码

class Solution {
public:
    bool isAnagram(string s, string t) {
        if(s.length()!=t.length()){
            return false;
        }
        vector<int> v(26,0);
        for(int i=0;i<s.length();i++){
            v[s[i]-'a']++;
        }
        for(int j=0;j<t.length();j++){
            v[t[j]-'a']--;
            if(v[t[j]-'a']<0){
                return false;
            }
        }
        return true;
    }
};

参考文献

​​[LeetCode] Valid Anagram 验证变位词​​