原题链接3. Longest Substring Without Repeating Characters
Given a string, find the length of the longest substring without repeating characters.
Example 1:
Input: "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.
Example 2:
Input: "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.
Example 3:
Input: "pwwkew"
Output: 3
Explanation: 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.
解题思路：为每一个字符开辟一个hashtable+滑动窗口进行求解，这样更新不重复子串的长度，得到最大值
func lengthOfLongestSubstring(s string) int {
var posi [256]int
for i,_ := range posi {
posi[i] = -1
}
curr_len, max_len, start := 0, 0, 0
for i, v := range s {
val := int(v)
if posi[val] == -1 {
curr_len += 1
} else {
if start < posi[val] {
start = posi[val]
}
curr_len = i - start
}
posi[val] = i
if curr_len > max_len {
max_len = curr_len
}
}
return max_len
}
