0953-verifying-an-alien-dictionary.go

func isAlienSorted(words []string, order string) bool {
    // first differing char
    // if word A is prefix of word B, word B must be AFTER word A
    orderInd := make(map[byte]int)
    for i := 0; i < len(order); i++ {
        orderInd[order[i]] = i
    }
    
    for i := 0; i < len(words) - 1; i++ {
        w1, w2 := words[i], words[i + 1]
        
        for j := 0; j < len(w1); j++ {
            if j == len(w2) {
                return false
            }
            
            if w1[j] != w2[j] {
                if orderInd[w2[j]] < orderInd[w1[j]] {
                    return false
                }
                break
            }
        }
    }
    return true
}