56 lines
1.6 KiB
C++
56 lines
1.6 KiB
C++
#include <cinttypes>
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#include <fstream>
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#include <iostream>
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#include <vector>
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bool substring_unique_copyless(std::vector<uint8_t> *s, size_t right, size_t length) {
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for (size_t i = (right-length); i<right; i++) {
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uint8_t c = (*s)[i]; //s[i];
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for (size_t j = (i+1); j<right; j++) {
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if ((*s)[j] == c) {
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return false;
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}
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}
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}
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return true;
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}
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size_t find_first_unique_run(std::vector<uint8_t> *s, size_t num, size_t skip) {
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for (size_t right = skip; right<s->size(); right++) {
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if (substring_unique_copyless(s, right, num)) {
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return right;
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}
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}
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return 0;
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}
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void run_once(std::vector<uint8_t> *s) {
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size_t four = find_first_unique_run(s, 4, 4);
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size_t fourteen = find_first_unique_run(s, 14, four);
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std::cout << "Part 1: " << four << '\n';
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std::cout << "Part 2: " << fourteen << '\n';
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}
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void run_many(std::vector<uint8_t> *s, size_t iterations) {
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size_t four = 0;
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size_t fourteen = 0;
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for (size_t i = 0; i<iterations; i++) {
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four = find_first_unique_run(s, 4, 4);
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fourteen = find_first_unique_run(s, 14, four);
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}
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std::cout << "Part 1: " << four << '\n';
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std::cout << "Part 2: " << fourteen << '\n';
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std::cout << "Completed " << iterations << " iterations\n";
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}
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int main() {
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std::ifstream input_file("input/6", std::ios::binary | std::ios::ate);
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const std::streamoff eof_position = static_cast<std::streamoff>(input_file.tellg());
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std::vector<uint8_t> input = std::vector<uint8_t>(eof_position);
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input_file.seekg(0, std::ios::beg);
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input_file.read(reinterpret_cast<char*>(input.data()), eof_position);
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// run_once(&input);
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run_many(&input, 1000000);
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}
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