77 lines
2.1 KiB
C++
77 lines
2.1 KiB
C++
/*/ problem source:
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* https://www.geeksforgeeks.org/find-the-longest-substring-with-k-unique-characters-in-a-given-string/
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*/
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#include <iostream>
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#include <ostream>
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#include <unordered_map>
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#include <vector>
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class result {
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public:
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unsigned long longest_start = 0;
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unsigned long longest_end = 0;
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bool match_found = false;
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bool operator==(const result r) {
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return longest_start == r.longest_start && longest_end == r.longest_end &&
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match_found == r.match_found;
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};
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};
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struct input {
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std::string s;
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unsigned long k;
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};
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struct test_case {
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input i;
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result r;
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};
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result find(const std::string &s, const unsigned long k) {
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result r;
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std::unordered_map<char, unsigned long> char_count;
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unsigned long start = 0, end = 0;
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for (; end < s.length(); end++) {
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char_count[s[end]] += 1;
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while (char_count.size() > k) {
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char_count[s[start]]--;
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if (char_count[s[start]] == 0) {
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char_count.erase(s[start]);
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}
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start++;
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}
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if (char_count.size() == k &&
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end - start > r.longest_end - r.longest_start) {
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r.longest_start = start, r.longest_end = end;
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r.match_found = true;
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}
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}
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if (r.match_found) {
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std::cout << "Longest substring is \""
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<< s.substr(r.longest_start, r.longest_end - r.longest_start + 1)
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<< "\" with length " << r.longest_end - r.longest_start + 1
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<< ".\n";
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} else {
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std::cout << "Could not find any match, not enough unique characters.\n";
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}
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return r;
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}
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int main() {
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std::vector<test_case> test_cases = {{{"aabacbebebe", 3}, {4, 10, true}},
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{{"aabbcc", 1}, {0, 1, true}},
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{{"aabbcc", 3}, {0, 5, true}},
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{{"aaabbb", 3}, {0, 0, false}}};
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for (const test_case &t : test_cases) {
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if (find(t.i.s, t.i.k) == t.r) {
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std::cout << "Test case with string \"" << t.i.s << "\" and k=" << t.i.k
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<< " passed.\n";
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} else {
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std::cout << std::flush;
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std::cerr << "TEST CASE WITH STRING \"" << t.i.s << "\" AND k=" << t.i.k
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<< " FAILED.\n";
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}
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}
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return 0;
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} |