Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for “abcabcbb” is “abc”, which the length is 3. For “bbbbb” the longest substring is “b”, with the length of 1.
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24public class Solution {
public int lengthOfLongestSubstring(String s) {
int[] map = new int[256]; //Map the character to the first occurence index
int max = 0;
int slow = 0;
Arrays.fill(map,-1);
for (int fast = 0; fast < s.length(); fast++){
char current = s.charAt(fast);
if (slow <= map[current]){
max = Math.max(max, fast - slow);
slow = map[current] + 1;
}
map[current] = fast;
}
max = Math.max(max, s.length() - slow);
return max;
}
}