Word pattern

A full match, such that there is a bijection between a letter in pattern and a non-empty word in s.

Go

Time complexity: $O(n)$ - n is a length of a pattern string
Auxiliary space: $O(n)$ - n is a length of an input string

import "fmt"

func wordPattern(pattern string, str string) bool {
    words := strings.Split(str, " ")

    if len(words) == 0 {
        return false
    }
    if len(words) != len(pattern) {
        return false
    }

    wordRuneMap := make(map[byte]string)
    wordPresenceMap := make(map[string]bool)

    for i := 0; i < len(pattern); i++ {
        rune, word := pattern[i], words[i]

        mappedWord, ok := wordRuneMap[rune]
        
        if ok {
            if mappedWord == word {
                continue
            }
            return false
        }

        present, ok := wordPresenceMap[word]
        if ok && present {
            return false
        }

        wordRuneMap[rune] = word
        wordPresenceMap[word] = true
    }
    
    return true
}

thoughtbook

Word pattern

Go