longest substring without repeating characters

Given a string, find the length of the longest substring without repeating characters.

Examples:

Given “abcabcbb”, the answer is “abc”, which the length is 3.

Given “bbbbb”, the answer is “b”, with the length of 1.

Given “pwwkew”, the answer is “wke”, with the length of 3. Note that the answer must be a substring, “pwke” is a subsequence and not a substring.

目的是想要截取到给定字符串中最长的不重复的字符串。

eg:
abcabcabc => abc

aaaaaaaababcd => abcd

aaaaaa => a

• golang 版本
  

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  func (s string) int { location := make([]int, 128) for i := 0; i < 128; i++ { location[i] = -1 } begin, length := -1, 0 for i, v := range s { if location[v] > begin{ begin = location[s[i]] } if (i - begin > length) { length = i - begin; } location[s[i]] = i; } return length }