LeetCode 242. Valid Anagram

[quinnwencn]

Description

Given two strings s and t, return true if t is an anagram of s, and false otherwise.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

Example 1:

Input: s = "anagram", t = "nagaram"
Output: true
Example 2:

Input: s = "rat", t = "car"
Output: false

Constraints:

1 <= s.length, t.length <= 5 * 104
s and t consist of lowercase English letters.

Follow up: What if the inputs contain Unicode characters? How would you adapt your solution to such a case?

[quinnwencn]

Analysis

This problem is a little similar to LeetCode 207. We can also map chars to index to solve it.

Solution written in Cpp

class Solution {
public:
    bool isAnagram(string s, string t) {
        int slen = s.length();
        if (slen != t.length()) {
            return false;
        }

        int letters[26] {0};
        for (int i = 0; i < slen; ++i) {
            letters[s[i] - 'a']++; 
        }

        for (int i = 0; i < slen; ++i) {
            letters[t[i] - 'a']--;
        }

        for (auto i : letters) {
            if (i != 0) {
                return false;
            }
        }

        return true;
    }
};

Solution written in Rust

impl Solution {
    pub fn is_anagram(s: String, t: String) -> bool {
        if s.len() != t.len() {
            return false;
        }

        let mut visited = vec![0; 26];
        let it = s.chars().zip(t.chars());
        for (c1, c2) in it {
            visited[c1 as usize - 'a' as usize] += 1;
            visited[c2 as usize - 'a' as usize] -= 1;
        }

        for i in visited {
            if i != 0 {
                return false;
            }
        }

        true
    }
}