40 lines
697 B
C++
40 lines
697 B
C++
// Determine if a string has all-unique characters.
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#define CATCH_CONFIG_MAIN
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#include <catch.hpp>
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#include <string>
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#include <unordered_set>
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#include <fmt/format.h>
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bool all_unique(const std::string& str) {
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std::unordered_set<char> seen;
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for (auto ch : str) {
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if (seen.find(ch) != seen.end()) {
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return false;
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}
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seen.emplace(ch);
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}
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return true;
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}
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bool all_unique_2(const std::string& str) {
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bool seen[1 << (sizeof(char) * 8)]{};
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for (int ch : str) {
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if (seen[ch]) {
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return false;
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}
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seen[ch] = true;
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}
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return true;
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}
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TEST_CASE("cc11", "all_unique") {
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REQUIRE(all_unique("abcdef") == true);
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REQUIRE(all_unique("foo bar") == false);
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}
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