953. Verifying an Alien Dictionary

O(m*n) time O(1) space where m is the avg length of a word while n is the number of words

class Solution {
public:
    bool isAlienSorted(vector<string>& words, string order) {
        int dict[26] = {0};
        for (int i = 0; i < 26; ++i) {
            dict[order[i] - 'a'] = i;
        }
        for (int i = 1; i < words.size(); ++i) {
            if (!lte(words[i - 1], words[i], dict)) return false;
        }
        return true;
    }

    bool lte(const string &a, const string &b, int dict[26]) {
        int m = a.length(), n = b.length();
        for (int i = 0; i < min(m, n); ++i) {
            if (a[i] == b[i]) continue;
            return dict[a[i] - 'a'] <= dict[b[i] - 'a'];
        }
        return m <= n;
    }
};