44 lines
1.1 KiB
C++
44 lines
1.1 KiB
C++
#include <unordered_set>
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#include <string>
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/**
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* 3. Longest Substring Without Repeating Characters
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* Given a string s, find the length of the longest substring without repeating characters.
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*
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* 100% same algorithm as -> 220612.cpp
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*/
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class Solution {
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public:
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static int lengthOfLongestSubstring(const std::string& str) {
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std::unordered_set<int> s;
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const int n = str.length();
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int sum = 0, ret = 0;
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for (int i = 0, l = 0; i < n; ++i) {
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std::printf("In loop, i = %d, l = %d\nStart inserting: ", i, l);
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for (; i < n && !s.count(str[i]); ++i) {
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++sum; // sum += str[i];
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s.insert(str[i]);
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std::printf("%d ", str[i]);
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}
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ret = std::max(ret, sum);
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if (i == n)
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break;
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std::printf("\nEnd inserting at position %d, str[i] = %d, updating ret <- %d\nStart popping: ", i, str[i], ret);
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// pop until reach str[i]
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for (; str[l] != str[i]; ++l) {
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s.erase(str[l]);
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--sum; // sum -= str[l];
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std::printf("%d ", str[l]);
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}
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++l; // where str[l] == str[i]
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std::printf("\nEnd loop, where i = %d, l = %d\n\n", i, l);
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}
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return ret;
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}
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};
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