leetcode/LongestSubstringWithoutRepeatingCharacters.java at master · baoxtech/leetcode

40 lines (35 loc) · 935 Bytes

import java.util.HashMap;

/**

* 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.

public class LongestSubstringWithoutRepeatingCharacters {

public int lengthOfLongestSubstring(String s) {

if (s.length() == 0)

return 0;

int i = 0, j = 0;

int result = 0;

HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();

while (j < s.length()) {

Integer c = new Integer(s.charAt(j));

if (!map.containsKey(c)) {

map.put(c, j);

} else {

int length = j - i;

if (result < length) {

result = length;

}

Integer index = map.get(c);

i = Math.max(i, index + 1);

map.put(c, j);

}

j++;

}

if (result < j - i)

return j - i;

else

return result;

}

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