#include <BAN/Vector.h> #include <BAN/Sort.h> #include <BAN/String.h> #include <ctype.h> #include <inttypes.h> #include <stdio.h> #include <stdint.h> using i64 = int64_t; i64 parse_i64(BAN::StringView part) { i64 result = 0; for (char c : part) { if (!isdigit(c)) break; result = (result * 10) + (c - '0'); } return result; } struct Hand { BAN::String hand; i64 bid; }; i64 card_score(char card, bool joker) { if (card == 'A') return 14; if (card == 'K') return 13; if (card == 'Q') return 12; if (card == 'J') return joker ? 1 : 11; if (card == 'T') return 10; ASSERT('2' <= card && card <= '9'); return card - '0'; } i64 hand_score_no_type(const Hand& hand, bool joker) { ASSERT(hand.hand.size() == 5); i64 score = 0; for (char c : hand.hand) score = (score << 4) | card_score(c, joker); ASSERT(score < 1'000'000); return score; } i64 hand_score(const Hand& hand, bool joker) { ASSERT(hand.hand.size() == 5); i64 joker_count = 0; i64 cnt[26 + 10] {}; for (char c : hand.hand) { if (isdigit(c)) cnt[c - '0' + 0]++; else if (joker && c == 'J') joker_count++; else cnt[c - 'A' + 10]++; } i64 freq_max1 = 0; i64 freq_max2 = 0; for (size_t i = 0; i < 36; i++) { if (cnt[i] > freq_max1) { freq_max2 = freq_max1; freq_max1 = cnt[i]; } else if (cnt[i] > freq_max2) { freq_max2 = cnt[i]; } } freq_max1 += joker_count; if (freq_max1 == 5) return 6'000'000 + hand_score_no_type(hand, joker); if (freq_max1 == 4) return 5'000'000 + hand_score_no_type(hand, joker); if (freq_max1 == 3 && freq_max2 == 2) return 4'000'000 + hand_score_no_type(hand, joker); if (freq_max1 == 3) return 3'000'000 + hand_score_no_type(hand, joker); if (freq_max1 == 2 && freq_max2 == 2) return 2'000'000 + hand_score_no_type(hand, joker); if (freq_max1 == 2) return 1'000'000 + hand_score_no_type(hand, joker); return hand_score_no_type(hand, joker); } i64 puzzle(FILE* fp, bool joker) { BAN::Vector<Hand> hands; char buffer[128]; while (fgets(buffer, sizeof(buffer), fp)) { BAN::StringView line(buffer); if (line.size() < 7) continue; MUST(hands.emplace_back( line.substring(0, 5), parse_i64(line.substring(6)) )); } BAN::sort::sort(hands.begin(), hands.end(), [joker] (const Hand& lhs, const Hand& rhs) { return hand_score(lhs, joker) < hand_score(rhs, joker); } ); i64 score = 0; for (size_t i = 0; i < hands.size(); i++) score += (i + 1) * hands[i].bid; return score; } int main(int argc, char** argv) { const char* file_path = "/usr/share/aoc2023/day7_input.txt"; if (argc >= 2) file_path = argv[1]; FILE* fp = fopen(file_path, "r"); if (fp == nullptr) { perror("fopen"); return 1; } printf("puzzle1: %" PRId64 "\n", puzzle(fp, false)); fseek(fp, 0, SEEK_SET); printf("puzzle2: %" PRId64 "\n", puzzle(fp, true)); fclose(fp); }