最长不重复子串

package main

import (
   "fmt "
)

func (str string) int {
  start := 0
  maxlen := 0
  lastO := make(map[rune]int)
  for i, v := range []rune(str) {
      if lastI, ok := lastO[v]; ok {
         start = lastI + 1
      }
      if (i-start+1 > maxlen) {
         maxlen = i - start + 1
      }
      lastO[v] = i
  }
  return maxlen
}

func main() {
  
  //s:=  "Yes哈哈哈! "
  fmt.Println(maxLen( "abcbcdef "))
  fmt.Println(maxLen( "abcdef "))
  fmt.Println(maxLen( "aaaaaaa "))
  fmt.Println(maxLen( "你说什么 "))
}