27 lines
900 B
C++
27 lines
900 B
C++
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#include "s0003_longest_substring_without_repeating_characters.hpp"
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int Solution::lengthOfLongestSubstring(std::string s) {
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// index_forward points to the frontmost element
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// index_backward points to the last repeated element
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//
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// for
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// check if index_forward pointed element exists in hash map
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// if exists, index_backward = max(index_backward, the index of
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// this element)
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// push
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// index_forward += 1
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// len = max(index_forward, index_backward)
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std::map<char, int> map;
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int index_backward{-1};
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int index_forward{0};
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int len{0};
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for (; index_forward < s.length(); index_forward++) {
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if (map.count(s[index_forward]) == 1) {
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index_backward = std::max(index_backward, map.at(s[index_forward]));
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}
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map[s[index_forward]] = index_forward;
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len = std::max(len, index_forward - index_backward);
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}
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return len;
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}
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