Boyer moore impl in go re: https://leetcode.com/problems/implement-strstr

boyer-mode.go

func strStr(haystack string, needle string) int {
    foundpos := -1
    if len(needle) < 1 {
        return 0
    }
    if len(needle) > len(haystack) { 
        return foundpos
    }
    
    /* Find unique char nearest the end of 'needle' to skip with */
    skipmap, skip := make(map[rune]int), rune(needle[0])
    for i, v := range needle {
        if _, ok := skipmap[v]; !ok {
            skipmap[v] = i
            skip = v 
        }
    }
    
    for i := skipmap[skip]; i < len(haystack); i++ {
        if s, ok := skipmap[rune(haystack[i])]; !ok {
            i += s
        } else if end := (i-s)+len(needle); end <= len(haystack) && needle == haystack[i-s:end] {
            return i-s
        }
    }
    
    return foundpos
}