953. Verifying an Alien Dictionary 

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class Solution {
    public boolean isAlienSorted(String[] words, String order) {
        int[] orderMap = new int[26];
        for (int i = 0; i < order.length(); i++) {
            orderMap[order.charAt(i) - 'a'] = i;
        }

        for (int i = 0; i < words.length - 1; i++) {
            if (greatThan(words[i], words[i + 1], orderMap)) {
                return false;
            }
        }

        return true;
    }

    private boolean greatThan(String wordA, String wordB, int[] orderMap) {
        for (int i = 0; i < wordA.length(); i++) {
            if (i == wordB.length()) {
                // wordA 更长
                return true;
            }
            int diff = orderMap[wordA.charAt(i) - 'a'] - orderMap[wordB.charAt(i) - 'a'];
            if (diff == 0) {
                continue;
            } else {
                return diff > 0;
            } 
        }

        return false;
    }
}

References

953. Verifying an Alien Dictionary
剑指 Offer II 034. 外星语言是否排序